The Long and Short of Portfolio Construction

Join Our Mailing List

Long-Short Portfolio Construction vs. Long-Only

[By Dr. David Edward Marcinko MBA CMP™]


Long-Short is an active portfolio construction discipline that balances long positions in high expected return securities and short positions in low expected return securities of approximately equal value and market sensitivity. This type of portfolio is “neutralized” or immunized against changes in value of the underlying market and, therefore, has zero systematic (beta) risk. If the selected securities perform as expected, the long-short positions will provide a positive return, whether the market rises or falls.


While long-short portfolios are often perceived and portrayed as much costlier and much riskier than long-only, it is inherently neither. Much of the incremental cost and risk is either largely dependent on the amount of leverage employed or controllable via optimization. Those costs and risks that are not controllable—financial intermediation costs of borrowing shares to short, the trading costs incurred to meet long-short balancing, margin requirements, uptick rules, and the risks of unlimited losses on short positions—do not invalidate the viability of long-short strategies.

Long-Short Advantages

Compared with long-only portfolios, long-short portfolios offer enhanced flexibility not only in the control of risk and pursuit of return, but also in asset allocation. Basic market-neutral portfolios achieve a return consisting of three components: (1) interest on funds held as a liquidity buffer, (2) interest on the short sale proceeds maintained with the broker, and (3) the return spread between the aggregate long and aggregate short positions in the portfolios.


Share borrow-ability and uptick rules make short-selling more difficult and costly than going long. Also, it may be legally or contractually restricted for some investors, such as mutual funds. Inefficiencies may be concentrated in overpriced stocks and, accordingly, short sales of the most overpriced stocks may offer higher positive returns than long purchases of underpriced stocks.


Long-only portfolios are confined to altering the weighting of securities within an index in order to realize an excess return. Long-short portfolios are not constrained by index weights and, because they can short securities, they can “underweight” a security by as much as investment insights and risk considerations dictate. Long-short portfolios can be enhanced by “equitizing” them using stock index futures.

Note: “The Long and Short on Long-Short” by Bruce I. Jacobs and Kenneth N. Levy, The Journal of Investing, Spring 1997, pp. 73–86, Institutional Investor, Inc.


Your thoughts and comments on this ME-P are appreciated. Feel free to review our top-left column, and top-right sidebar materials, links, URLs and related websites, too. Then, subscribe to the ME-P. It is fast, free and secure.

Speaker: If you need a moderator or speaker for an upcoming event, Dr. David E. Marcinko; MBA – Publisher-in-Chief of the Medical Executive-Post – is available for seminar or speaking engagements. Contact:


Product DetailsProduct DetailsProduct Details***

5 Responses

  1. Despite Ill Winds – Health Stocks Look Healthy

    Health stocks have faced strong headwinds. The sluggish economy has caused patients to postpone elective surgery, while pharmaceutical companies have been hurt by healthcare reform and expirations of patents on blockbuster drugs.

    And so, should we avoid health stocks – or not?



  2. FINRA Fines Credit Suisse Securities $1.75 Million Dollars

    The Financial Industry Regulatory Authority (FINRA) has fined Credit Suisse Securities (USA) LLC $1.75 million for allegedly failing to properly supervise short sales of securities and marking of sale orders.



  3. Dr. Marcinko

    Very interesting and helpful.
    Thank you.

    Dr. Boyd


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: