A.W. Jones - The Original Hedge Fund
Measuring Market Risk
Jones was light-years ahead of both Wall Street practitioners and the academic community in developing an understanding of market risk as well as the relationship between individual stocks and the market. Before the academic community had codified the Capital Asset Pricing Model (CAPM) with its notion of Alpha and Beta, Jones had developed his own measure of market risk and how individual stocks related to the market. Even more astonishing is that he was actively managing the exposure of a risk-adjusted portfolio with this system.
Jones calculated a metric for each stock called Relative Velocity, which is closely related to the CAPM's Beta (the key difference being the omission of the risk-free rate in the calculation of Velocity). Relative Velocity was the tendency of a stock, based on historical performance, to move with the S&P 500 to a greater or lesser degree. Armed with this metric, the firm could then calculate to what extent its long book and short book were correlated with market moves. What follows below is an excerpt from the 1961 Basic Report to the Limited Partners of the firm, describing in detail the measurement and management of market risk.
From the 1961 Basic Report to the Limited Partners:
ON MEASUREMENT AND REPORTING
This is our post-graduate course. It should be taken by all
partners and must be taken by those who wish fully to
understand our bi-monthly reports.
In the main body of this communication we described our
investment theories and explained at least the basis of our
method. It now must be made clear that such a program cannot
be put into operation without careful and continuous
controls. We have developed methods which provide accurate
measurement of the degree of risk being taken at all times
as well as a system of allocation by which we determine
whether our gains or losses are attributable to stock
selection or to the trend of the market. Daily computations
using this method enable us to see where we stand and permit
us to plan any desirable changes with regard to market risk.
In addition we have a moving record of our accomplishments
in market or stock-selection judgment.
Relative Velocity
Different stocks habitually move up and down at different
rates of speed, and hedging $1,000 worth of a stodgy stock
against $1,000 worth of a fast mover would give no true
balance of risk. We must therefore compute the velocity of
all our stocks, both long and short, by their past
performance, compared with the past performance of a good
measure of the market as a whole. For this we use Standard
and Poor's 500 Stock Index, which we consider the most
scientifically constructed of the several averages. We shall
refer to it below merely as the Standard 500.
We measure, for example, the size or amplitude of all the
significant swings in the price of Sears Roebuck since 1948
against the corresponding swings in the Standard 500 and
find that the average extent of these moves is 80 per cent
of the average extent of the moves of the Standard 500. We
say therefore that the Relative Velocity of Sears is 80.
By the same measurement (which we have made and which we
bring up to date at about two-year intervals for over 2,000
stocks ) we find that the velocity of the stock of General
Dynamics is 1.96. Obviously, to buy and sell short,
respectively, equal dollar amounts of Sears and General
Dynamics would constitute no true hedge. Instead there would
have to be more than twice as much of the stable Sears stock
as of the volatile Dynamics to cause them to offset each
other in market risk.
To illustrate :
It must be pointed out that relative velocity has nothing
directly to do with the desirability of a stock. All a
velocity measurement does for us is to measure one aspect of
the risk we are taking when we buy it or sell it short.
Either Sears or General Dynamics might be a good purchase or
a good sale, depending on all the factors that go into stock
selection. From here on all the amounts used in the various
examples of aggregate stock holdings will be dollar amounts
after correction for velocity.
Since the Standard 500 is composed mostly of the big "blue
chips," which move slowly, a portfolio of stocks commonly
used for investment by us will have an average velocity over
100. Thus a list of typical stocks worth $70,000 to $80,000
in cash, might come to $100,000 after correcting for
velocity (cash times velocity in each individual stock.)
Measurement of Results
Let us now take the simplest of cases -- a fund of $100,000
equity or net worth, with $100,000 of long positions and
$100,000 of short positions (each position computed in cash
times velocity.) Such a fund, being fully hedged, has a
market risk of zero and all net gains or losses will be
attributable to good or bad stock selection, none to the
action of the market.
For six months we maintain this even balance between long
and short (this could hardly happen in actual practice,)
though we shall certainly make shifts during the period
within both the long and short list, thus realizing profits
and losses, and then replacing the long stocks sold and the
short stocks covered. Every day from the newspaper stock
tables we calculate our gains and losses, arriving at a net
figure for the long list and a net figure for the short
list. These two figures are kept cumulatively and include
both unrealized and realized gains and losses. By the end of
six months, the following has happened:
This is fine as far as it goes. It tells us that we have made $7,000 by good stock selection (since we are fully
hedged), but it doesn't tell us how to allocate the gain as
between long and short selection—perhaps we should have made
more on the long side, in the market rise, or perhaps lost
less an the short side. So the following further
calculations are necessary:
1) Just to keep pace with the "market" rise of 5%, our long
stocks, worth $100,000 should go up by $5,000. But in fact
they went up by $9,000. The difference, attributable to good
long stock selection, is $4,000.
2) Also to match the rise in the market, our $100,000 worth
of short stocks should have gone up, showing us a loss of $5,000. Actually they went up only $2,000, and the difference, due to good short stock selection, is $3000.
3) For a total gain, to account for the net gain shown
above, of $7,000.
With an Unhedged Balance
When we are not fully hedged, but have a net-long (as is
usually the case) or a net-short balance, the operation has
an added complication. Suppose now, still with $100,000 of
equity, we are optimistic about the stock market, so we buy
stocks worth $130,000 and sell short stocks worth $70,000.
We hold this balance (though we may shift individual stocks)
for one week, during which time the following happenes:
Reporting
Our reports go to a good many persons besides yourselves,
and because we do not wish to reveal to all who receive them
the size of the fund, also in order to indicate more clearly to you the change in your own partnership share, the figures
for gains and losses are not stated in dollar amounts but in
percentages of our net worth at the beginning of the fiscal
year. Therefore if the week's results illustrated above were
for the first week of the year, the report for that week
would read:
Progress : Since June 1, our fund has gained 2.1% against a gain of 1.0% in the Standard
500. On long stocks we show a gain and on short stocks a loss of 0.4%
These figures are the result of calculations made every day
and kept cumulatively for the entire fiscal year. They
include both unrealized and realized gains and losses for
the period from the beginning of the fiscal year, and are
calculated after brokerage expense and transfer taxes on all
transactions that have taken place.
The reports take into account dividends received on long
stock and dividends paid on short stack. They take into
account also, at monthly intervals in our cumulative
reckoning, the interest we pay to banks and brokers.
However, the reports overstate the eventual return to you,
since they cannot conveniently, and do not, take into
account the 20 per cent of realized capital gains paid over
to management at the end of the fiscal year. Also, as the
year goes on, the reports become more and more unfair in the
comparison with the Standard 500 since to the latter should
be added a small percentage as dividend yield.
We used to report regularly and we still do report
occasionally the amount that we are making in the hedged
part of the fund alone. In the example above, the hedged
part of the fund is the entire minority, or short list,
($70,000) combined with an offsetting $70,000 of the long
list. The entire long list being $130, 000, the hedged part
of it is 7/13 of the whole. We now find how much we have
made in the hedged part by the following calculation:
We keep this figure cumulatively during the fiscal year,
reporting it also as a percentage (in this case 0.9%) of our
equity. By a somewhat complicated method we calculate from
it what we make on the hedged part of the fund as a percentage of the money actually used in it. This is a gain
obtained without risk due to the trend of the stock market,
and not to be had by any other form of investment
procedure.
The Risk Figure
In the Market Judgment section of the reports you see a
number variously called the risk figure, market risk, or
percentage of risk in the Standard 500. From the above it is
easy to see how this is obtained. Remember that our list of
long stocks aggregates $130,000 only after the cash value of
each stock in it has been multiplied by its velocity,
relative to the Standard 500. This relates our long stocks
to the Standard 500, so that $130,000 long gives us a risk
on the long side alone (our equity being $100,000) of
$130,000 divided by $100,000, or 1.3. Instead of using a
decimal fraction we use a percentage and say that our long
side risk is 130. By the same reasoning, our short risk,
also exactly related to the risk in the "market", or
Standard 500, is 0.7, or 70 per cent. Our net-long risk is
therefore 60 (130 minus 70), which means that our net-long
risk in the stock market is equal to 60 per cent of the risk
we would be taking if we had our whole equity exactly
invested in the stocks of the Standard 500.
Any minus figure will stand for a net-short balance, in
which we gain from a decline in the stock market. At plus
40, say, we would be incurring about the market risk of a
widow with half her money in somewhat stodgy, blue-chip
common stocks and half in bonds. At plus 100 to 150 we would
be taking the risks of a business man with most or all of
his capital in more volatile stocks.
Containing, as it does, the velocity measurements of all of
our stocks relative to the Standard 500, the risk figure is
a very precise measurement of just what we want to measure.
It enables us to adjust our position in the market exactly
to our outlook for its probable future trend.
A.W. Jones - The Original Hedge Fund
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