MS

March 2023

Preliminary Terms No. 8,593

Registration Statement Nos. 333-250103; 333-250103-01

Dated March 29, 2023

Filed pursuant to Rule 433

Morgan Stanley Finance LLC

Structured Investments

Opportunities in International Equities

Market-Linked Notes due April 2, 2026

Based on the Value of the EURO STOXX 50® Index

Fully and Unconditionally Guaranteed by Morgan Stanley

The notes are unsecured obligations of Morgan Stanley Finance LLC (“MSFL”) and are fully and unconditionally guaranteed by Morgan Stanley. The notes will pay no interest and will have the terms described in the accompanying product supplement, index supplement and prospectus, as supplemented and modified by this document. At maturity, we will pay per note the stated principal amount of $1,000 plus a supplemental redemption amount, if any, based on the value of the underlying index on the final observation date, subject to the maximum payment at maturity. The notes are for investors who are concerned about principal risk but seek an equity index-based return, and who are willing to forgo current income and upside beyond the maximum payment at maturity in exchange for the repayment of principal at maturity plus the potential to receive a supplemental redemption amount, if any. The notes are notes issued as part of MSFL’s Series A Global Medium-Term Notes program.

All payments are subject to our credit risk. If we default on our obligations, you could lose some or all of your investment. These notes are not secured obligations and you will not have any security interest in, or otherwise have any access to, any underlying reference asset or assets.

(1)J.P. Morgan Securities LLC and JPMorgan Chase Bank, N.A. will act as placement agents for the notes. The placement agents will forgo fees for sales to certain fiduciary accounts. The total fees represent the amount that the placement agents receive from sales to accounts other than such fiduciary accounts. The placement agents will receive a fee from the Issuer or one of its affiliates that will not exceed $20 per $1,000 stated principal amount of notes.

(2)Please see “Supplemental information regarding plan of distribution; conflicts of interest” in these preliminary terms for information about fees and commissions.

(3)See “Use of proceeds and hedging” on page 11.

The notes involve risks not associated with an investment in ordinary debt securities. See “Risk Factors” beginning on page 5.

The Securities and Exchange Commission and state securities regulators have not approved or disapproved these notes, or determined if this document or the accompanying product supplement, index supplement and prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The notes are not deposits or savings accounts and are not insured by the Federal Deposit Insurance Corporation or any other governmental agency or instrumentality, nor are they obligations of, or guaranteed by, a bank.

You should read this document together with the related product supplement, index supplement and prospectus, each of which can be accessed via the hyperlinks below. Please also see “Additional Terms of the Notes” and “Additional Information About the Notes” at the end of this document.

As used in this document, “we,” “us” and “our” refer to Morgan Stanley or MSFL, or Morgan Stanley and MSFL collectively, as the context requires.

 Product Supplement for Equity-Linked Notes dated November 16, 2020  Index Supplement dated November 16, 2020

 Prospectus dated November 16, 2020

Morgan Stanley

Morgan Stanley Finance LLC

Market-Linked Notes due April 2, 2026

Based on the Value of the EURO STOXX 50® Index

Investment Summary

Market-Linked Notes

The Market-Linked Notes due April 2, 2026 Based on the Value of the EURO STOXX 50® Index (the “notes”) offer 100% participation in the positive performance of the underlying index, subject to the maximum payment at maturity. The notes provide investors:

￭an opportunity to gain exposure to the EURO STOXX 50® Index

￭the repayment of principal at maturity, subject to our creditworthiness

￭100% participation in any appreciation of the underlying index over the term of the notes, subject to the maximum payment at maturity of at least $1,549.50 per note (154.95% of the stated principal amount). The actual maximum payment at maturity will be determined on the pricing date.

￭no exposure to any decline of the underlying index if the notes are held to maturity

At maturity, if the underlying index has depreciated or has not appreciated at all, you will receive the stated principal amount of $1,000 per note, without any positive return on your investment. All payments on the notes, including the repayment of principal at maturity, are subject to our credit risk.

The original issue price of each note is $1,000. This price includes costs associated with issuing, selling, structuring and hedging the notes, which are borne by you, and, consequently, the estimated value of the notes on the pricing date will be less than $1,000. We estimate that the value of each note on the pricing date will be approximately $972.40, or within $30.00 of that estimate. Our estimate of the value of the notes as determined on the pricing date will be set forth in the final pricing supplement.

What goes into the estimated value on the pricing date?

In valuing the notes on the pricing date, we take into account that the notes comprise both a debt component and a performance-based component linked to the underlying index. The estimated value of the notes is determined using our own pricing and valuation models, market inputs and assumptions relating to the underlying index, instruments based on the underlying index, volatility and other factors including current and expected interest rates, as well as an interest rate related to our secondary market credit spread, which is the implied interest rate at which our conventional fixed rate debt trades in the secondary market.

What determines the economic terms of the notes?

In determining the economic terms of the notes, including the participation rate and the maximum payment at maturity, we use an internal funding rate, which is likely to be lower than our secondary market credit spreads and therefore advantageous to us. If the issuing, selling, structuring and hedging costs borne by you were lower or if the internal funding rate were higher, one or more of the economic terms of the notes would be more favorable to you.

What is the relationship between the estimated value on the pricing date and the secondary market price of the notes?

The price at which MS & Co. purchases the notes in the secondary market, absent changes in market conditions, including those related to the underlying index, may vary from, and be lower than, the estimated value on the pricing date, because the secondary market price takes into account our secondary market credit spread as well as the bid-offer spread that MS & Co. would charge in a secondary market transaction of this type and other factors. However, because the costs associated with issuing, selling, structuring and hedging the notes are not fully deducted upon issuance, for a period of up to 6 months following the issue date, to the extent that MS & Co. may buy or sell the notes in the secondary market, absent changes in market conditions, including those related to the underlying index, and to our secondary market credit spreads, it would do so based on values higher than the estimated value. We expect that those higher values will also be reflected in your brokerage account statements.

MS & Co. may, but is not obligated to, make a market in the notes, and, if it once chooses to make a market, may cease doing so at any time.

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Morgan Stanley Finance LLC

Market-Linked Notes due April 2, 2026

Based on the Value of the EURO STOXX 50® Index

Key Investment Rationale

Market-Linked Notes offer investors exposure to the performance of equities or equity indices and provide for the repayment of principal at maturity. They are for investors who are concerned about principal risk but seek an equity index-based return, and who are willing to forgo yield in exchange for the repayment of principal at maturity plus the potential to receive a supplemental redemption amount, if any, based on the performance of the underlying index, subject to the maximum payment at maturity.

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Morgan Stanley Finance LLC

Market-Linked Notes due April 2, 2026

Based on the Value of the EURO STOXX 50® Index

Hypothetical Payout on the Notes

At maturity, for each $1,000 stated principal amount of notes that you hold, you will receive the stated principal amount of $1,000 plus a supplemental redemption amount, if any, subject to the maximum payment at maturity. The supplemental redemption amount will be calculated on the final observation date as follows:

(i) $1,000 multiplied by (ii) the index percent change multiplied by (iii) the participation rate of 100%, provided that the supplemental redemption amount will not be less than $0 or greater than at least $549.50 per note (to be determined on the pricing date).

In no event will the payment at maturity be less than the stated principal amount or greater than the maximum payment at maturity of at least $1,549.50 per note (154.95% of the stated principal amount). The actual maximum payment at maturity will be determined on the pricing date.

The table below illustrates the payment at maturity for each note for a hypothetical range of index percent change and does not cover the complete range of possible payouts at maturity. The table assumes a hypothetical initial index value of 4,000.00 and a hypothetical maximum payment at maturity of $1,549.50 per note. The actual initial index value and maximum payment at maturity will be determined on the pricing date.

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Morgan Stanley Finance LLC

Market-Linked Notes due April 2, 2026

Based on the Value of the EURO STOXX 50® Index

Risk Factors

This section describes the material risks relating to the notes. For further discussion of these and other risks, you should read the section entitled “Risk Factors” in the accompanying product supplement, index supplement and prospectus. We also urge you to consult your investment, legal, tax, accounting and other advisers in connection with your investment in the notes.

Risks Relating to an Investment in the Notes

￭The notes do not pay interest and may not pay more than the stated principal amount at maturity. If the index percent change is less than or equal to 0%, you will receive only the stated principal amount of $1,000 for each note you hold at maturity. As the notes do not pay any interest, if the underlying index does not appreciate sufficiently over the term of the notes, the overall return on the notes (the effective yield to maturity) may be less than the amount that would be paid on a conventional debt security of ours of comparable maturity. The notes have been designed for investors who are willing to forgo market floating interest rates in exchange for a supplemental redemption amount, if any, based on the performance of the underlying index.

￭The appreciation potential of the notes is limited by the maximum payment at maturity. The appreciation potential of the notes is limited by the maximum payment at maturity of at least $1,549.50 per note, or 154.95% of the stated principal amount. The actual maximum payment at maturity will be determined on the pricing date. Because the payment at maturity will be limited to 154.95% of the stated principal amount for the notes, any increase in the level of the index beyond 154.95% of the initial index value will not further increase the return on the notes.

￭The market price of the notes will be influenced by many unpredictable factors. Several factors will influence the value of the notes in the secondary market and the price at which MS & Co. may be willing to purchase or sell the notes in the secondary market, including the value of the underlying index at any time and, in particular, on the final observation date, the volatility (frequency and magnitude of changes in value) of the underlying index, dividend rate on the stocks underlying the index, interest and yield rates in the market, time remaining until the notes mature, geopolitical conditions and economic, financial, political, regulatory or judicial events that affect the underlying index or equities markets generally and which may affect the final index value of the underlying index and any actual or anticipated changes in our credit ratings or credit spreads. Generally, the longer the time remaining to maturity, the more the market price of the notes will be affected by the other factors described above. The value of the underlying index may be, and has recently been, volatile, and we can give you no assurance that the volatility will lessen. See “EURO STOXX 50® Index Overview” below. You may receive less, and possibly significantly less, than the stated principal amount per note if you try to sell your notes prior to maturity.

￭The notes are subject to our credit risk, and any actual or anticipated changes to our credit ratings or credit spreads may adversely affect the market value of the notes. You are dependent on our ability to pay all amounts due on the notes at maturity and therefore you are subject to our credit risk. The notes are not guaranteed by any other entity. If we default on our obligations under the notes, your investment would be at risk and you could lose some or all of your investment. As a result, the market value of the notes prior to maturity will be affected by changes in the market’s view of our creditworthiness. Any actual or anticipated decline in our credit ratings or increase in the credit spreads charged by the market for taking our credit risk is likely to adversely affect the market value of the notes.

￭As a finance subsidiary, MSFL has no independent operations and will have no independent assets. As a finance subsidiary, MSFL has no independent operations beyond the issuance and administration of its securities and will have no independent assets available for distributions to holders of MSFL securities if they make claims in respect of such securities in a bankruptcy, resolution or similar proceeding. Accordingly, any recoveries by such holders will be limited to those available under the related guarantee by Morgan Stanley and that guarantee will rank pari passu with all other unsecured, unsubordinated obligations of Morgan Stanley. Holders will have recourse only to a single claim against Morgan Stanley and its assets under the guarantee. Holders of securities issued by MSFL should accordingly assume that in any such proceedings they would not have any priority over and should be treated pari passu with the claims of other unsecured, unsubordinated creditors of Morgan Stanley, including holders of Morgan Stanley-issued securities.

￭The amount payable on the notes is not linked to the value of the underlying index at any time other than the final observation date. The final index value will be based on the index closing value on the final observation date, subject to postponement for non-index business days and certain market disruption events. Even if the value of the underlying index appreciates prior to the final observation date but then drops by the final observation date, the payment at maturity may be less, and may be significantly less, than it would have been had the payment at maturity been linked to the value of the underlying index prior to such drop. Although the actual value of the underlying index on the stated maturity date or at other times during the term of the notes may be higher than the final index value on the final observation date, the payment at maturity will be based solely on the final index value on the final observation date.

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Morgan Stanley Finance LLC

Market-Linked Notes due April 2, 2026

Based on the Value of the EURO STOXX 50® Index

￭The rate we are willing to pay for securities of this type, maturity and issuance size is likely to be lower than the rate implied by our secondary market credit spreads and advantageous to us. Both the lower rate and the inclusion of costs associated with issuing, selling, structuring and hedging the notes in the original issue price reduce the economic terms of the notes, cause the estimated value of the notes to be less than the original issue price and will adversely affect secondary market prices. Assuming no change in market conditions or any other relevant factors, the prices, if any, at which dealers, including MS & Co., may be willing to purchase the notes in secondary market transactions will likely be significantly lower than the original issue price, because secondary market prices will exclude the issuing, selling, structuring and hedging-related costs that are included in the original issue price and borne by you and because the secondary market prices will reflect our secondary market credit spreads and the bid-offer spread that any dealer would charge in a secondary market transaction of this type as well as other factors.

The inclusion of the costs of issuing, selling, structuring and hedging the notes in the original issue price and the lower rate we are willing to pay as issuer make the economic terms of the notes less favorable to you than they otherwise would be.

However, because the costs associated with issuing, selling, structuring and hedging the notes are not fully deducted upon issuance, for a period of up to 6 months following the issue date, to the extent that MS & Co. may buy or sell the notes in the secondary market, absent changes in market conditions, including those related to the underlying index, and to our secondary market credit spreads, it would do so based on values higher than the estimated value, and we expect that those higher values will also be reflected in your brokerage account statements.

￭The estimated value of the notes is determined by reference to our pricing and valuation models, which may differ from those of other dealers and is not a maximum or minimum secondary market price. These pricing and valuation models are proprietary and rely in part on subjective views of certain market inputs and certain assumptions about future events, which may prove to be incorrect. As a result, because there is no market-standard way to value these types of securities, our models may yield a higher estimated value of the notes than those generated by others, including other dealers in the market, if they attempted to value the notes. In addition, the estimated value on the pricing date does not represent a minimum or maximum price at which dealers, including MS & Co., would be willing to purchase your notes in the secondary market (if any exists) at any time. The value of your notes at any time after the date of this document will vary based on many factors that cannot be predicted with accuracy, including our creditworthiness and changes in market conditions. See also “The market price of the notes will be influenced by many unpredictable factors” above.

￭Investing in the notes is not equivalent to investing in the underlying index. Investing in the notes is not equivalent to investing in the underlying index or its component stocks. As an investor in the notes, you will not have voting rights or rights to receive dividends or other distributions or any other rights with respect to stocks that constitute the underlying index. See “Hypothetical Payout on the Notes” above.

￭The notes will not be listed on any securities exchange and secondary trading may be limited. The notes will not be listed on any securities exchange. Therefore, there may be little or no secondary market for the notes. MS & Co. may, but is not obligated to, make a market in the notes and, if it once chooses to make a market, may cease doing so at any time. When it does make a market, it will generally do so for transactions of routine secondary market size at prices based on its estimate of the current value of the notes, taking into account its bid/offer spread, our credit spreads, market volatility, the notional size of the proposed sale, the cost of unwinding any related hedging positions, the time remaining to maturity and the likelihood that it will be able to resell the notes. Even if there is a secondary market, it may not provide enough liquidity to allow you to trade or sell the notes easily. Since other broker-dealers may not participate significantly in the secondary market for the notes, the price at which you may be able to trade your notes is likely to depend on the price, if any, at which MS & Co. is willing to transact. If, at any time, MS & Co. were to cease making a market in the notes, it is likely that there would be no secondary market for the notes. Accordingly, you should be willing to hold your notes to maturity.

￭The calculation agent, which is a subsidiary of Morgan Stanley and an affiliate of MSFL, will make determinations with respect to the notes. As calculation agent, MS & Co. will determine the initial index value and the final index value, and will calculate the amount of cash you will receive at maturity. Moreover, certain determinations made by MS & Co., in its capacity as calculation agent, may require it to exercise discretion and make subjective judgments, such as with respect to the occurrence or non-occurrence of market disruption events and the selection of a successor index or calculation of the index closing value in the event of a discontinuance of the underlying index. These potentially subjective determinations may adversely affect the payout to you at maturity. For further information regarding these types of determinations, see “Description of Equity-Linked Notes—Supplemental Redemption Amount,” “—Calculation Agent and Calculations,” “—Alternate Exchange Calculation in the Case of an Event of Default” and “—Discontinuance of Any Underlying Index; Alteration of Method of Calculation” in the accompanying product supplement for equity-linked notes. In addition, MS & Co. has determined the estimated value of the notes on the pricing date.

￭Hedging and trading activity by our affiliates could potentially adversely affect the value of the notes. One or more of our affiliates and/or third-party dealers expect to carry out hedging activities related to the notes (and to other instruments linked to

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Morgan Stanley Finance LLC

Market-Linked Notes due April 2, 2026

Based on the Value of the EURO STOXX 50® Index

the underlying index or its component stocks), including trading in the stocks that constitute the underlying index as well as in other instruments related to the underlying index. As a result, these entities may be unwinding or adjusting hedge positions during the term of the notes, and the hedging strategy may involve greater and more frequent dynamic adjustments to the hedge as the final observation date approaches. Some of our affiliates also trade the stocks that constitute the underlying index and other financial instruments related to the underlying index on a regular basis as part of their general broker-dealer and other businesses. Any of these hedging or trading activities on or prior to the pricing date could potentially increase the initial index value, and, therefore, could increase the value at or above which the underlying index must close on the final observation date before you would receive at maturity a payment that exceeds the stated principal amount of the notes. Additionally, such hedging or trading activities during the term of the notes, including on the final observation date, could adversely affect the closing value of the underlying index on the final observation date, and, accordingly, the amount of cash an investor will receive at maturity.

Risks Relating to the Underlying Index

￭There are risks associated with investments in securities linked to the value of foreign equity securities. The notes are linked to the value of foreign equity securities. Investments in securities linked to the value of foreign equity securities involve risks associated with the securities markets in those countries, including risks of volatility in those markets, governmental intervention in those markets and cross-shareholdings in companies in certain countries. Also, there is generally less publicly available information about foreign companies than about U.S. companies that are subject to the reporting requirements of the United States Securities and Exchange Commission, and foreign companies are subject to accounting, auditing and financial reporting standards and requirements different from those applicable to U.S. reporting companies. The prices of securities issued in foreign markets may be affected by political, economic, financial and social factors in those countries, or global regions, including changes in government, economic and fiscal policies and currency exchange laws. Local securities markets may trade a small number of securities and may be unable to respond effectively to increases in trading volume, potentially making prompt liquidation of holdings difficult or impossible at times. Moreover, the economies in such countries may differ favorably or unfavorably from the economy in the United States in such respects as growth of gross national product, rate of inflation, capital reinvestment, resources, self-sufficiency and balance of payment positions between countries.

￭Adjustments to the underlying index could adversely affect the value of the notes. The publisher of the underlying index can add, delete or substitute the stocks underlying the index, and can make other methodological changes required by certain events relating to the underlying stocks, such as stock dividends, stock splits, spin-offs, rights offerings and extraordinary dividends, that could change the value of the underlying index. Any of these actions could adversely affect the value of the notes. The publisher of the underlying index may also discontinue or suspend calculation or publication of the underlying index at any time. In these circumstances, MS & Co., as the calculation agent, will have the sole discretion to substitute a successor index that is comparable to the discontinued index. MS & Co. could have an economic interest that is different than that of investors in the notes insofar as, for example, MS & Co. is permitted to consider indices that are calculated and published by MS & Co. or any of its affiliates. If MS & Co. determines that there is no appropriate successor index on such final observation date, the index closing value on the final observation date will be an amount based on the values of the stocks underlying the discontinued index at the time of such discontinuance, without rebalancing or substitution, computed by MS & Co, as calculation agent, in accordance with the formula for calculating the index closing value last in effect prior to discontinuance of the underlying index.

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Morgan Stanley Finance LLC

Market-Linked Notes due April 2, 2026

Based on the Value of the EURO STOXX 50® Index

EURO STOXX 50® Index Overview

The EURO STOXX 50® Index was created by STOXX Limited, a part of Qontigo, which is a wholly owned subsidiary of Deutsche Börse AG. Publication of the EURO STOXX 50® Index began on February 26, 1998, based on an initial index value of 1,000 at December 31, 1991. The EURO STOXX 50® Index is composed of 50 component stocks of market sector leaders among the 20 STOXX supersectors, which includes stocks selected from the Eurozone. The component stocks have a high degree of liquidity and represent the largest companies across all market sectors. For additional information about the EURO STOXX 50® Index, see the information set forth under “EURO STOXX 50® Index” in the accompanying index supplement.

Information as of market close on March 24, 2023:

The following graph sets forth the daily index closing values of the underlying index for each quarter in the period from January 1, 2018 through March 24, 2023. The related table sets forth the published high and low closing values, as well as end-of-quarter closing values, of the underlying index for each quarter in the same period. The index closing value of the underlying index on March 24, 2023 was 4,130.62. We obtained the information in the table and graph below from Bloomberg Financial Markets, without independent verification. The underlying index has at times experienced periods of high volatility. You should not take the historical values of the underlying index as an indication of its future performance, and no assurance can be given as to the index closing value of the underlying index on the final observation date.

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Morgan Stanley Finance LLC

Market-Linked Notes due April 2, 2026

Based on the Value of the EURO STOXX 50® Index

“EURO STOXX 50®” and “STOXX®” are registered trademarks of STOXX Limited. See “EURO STOXX 50® Index” in the accompanying index supplement.

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Morgan Stanley Finance LLC

Market-Linked Notes due April 2, 2026

Based on the Value of the EURO STOXX 50® Index

Additional Terms of the Notes

Please read this information in conjunction with the summary terms on the front cover of this document.

March 2023 Page 10 

Morgan Stanley Finance LLC

Market-Linked Notes due April 2, 2026

Based on the Value of the EURO STOXX 50® Index

Additional Information About the Notes

March 2023 Page 11 

Morgan Stanley Finance LLC

Market-Linked Notes due April 2, 2026

Based on the Value of the EURO STOXX 50® Index

March 2023 Page 12