In a direct way, more and more private investors are selling FX
options, thereby carefully adjusting the amount of leverage they wish
to take. Such positions are risk-managed on a dynamic basis. Investors
actively trade their position and use take-profit and stop-loss orders
in the options as well as in the forwards market.
This is time-consuming for the investor since a whole universe of data
is available for the decision-making. Even for professional FX traders
it is hard to get a complete overview. Only a few of those indicators
are actively looked at. These indicators are generally of a complicated
nature and not easily accessible to a general audience.
Yield enhancement
A more indirect way of selling implied volatility has emerged with the
dawn of FX yield enhancement products. In most cases, a buyer of such
products is implicitly selling options.
As a result most market-making option books now have a more or less
constant supply of vega and even the very much needed volgamma. This
supply of options has a risk-reducing effect for the market makers. It
partially offsets the corporate, institutional and speculative demand
for vega. For those market-making banks, the risk is reduced even
further due to the fact that these yield enhancement products are
traded fully-funded. There is no leverage added, and no show-stopping
credit limits need to be in place.
To this end, the current situation in the FX options market has
positive effects on the global FX markets. The balance between option
buyers and sellers has clearly shifted to become more neutral.
Risk reduction
There are several reasons for this shift.
A great portion of the vega supply stems from FX yield enhancement
products bought by private clients. These products are even bought by
individuals who would generally not buy or sell the components alone
(because the individual components seem too risky).
So why buy the package?
This question needs a closer look. It is much too simple to just think
that a packaged solution sells because it pays a high yield. Above
money market yields could be achieved in several other ways as well.
Therefore more insight might be gained by looking at an older concept –
a strategy that emerged from the first days of option trading: the
so-called buy-write.
Basic strategies
In option textbooks and derivatives classes, the most common basic
strategies are protective-put and buy-write. Both strategies are built
of a core long position in an underlying (e.g. a company share or a US
dollar deposit) plus a long/short position in an option. The
protective-put adds a long put option to the underlying and therefore
creates a synthetic long call position. The buy-write adds a short call
option to the underlying and creates a synthetic short put position.
At a first glance, the protective-put position seems to be risk-reducing. The buy-write looks like the opposite.
A closer look though reveals a slightly different picture.
The biggest difference between the two positions is the premium. The
protective-put is a negative cash flow as opposed to the buy-write,
where a premium is paid to the holder. So even though the upside is
limited to the buy-write, one already begins with money in the pocket.
This can be viewed as a discount on the price of the underlying.
On the other hand, the protective-put holder can be seen as buying the
underlying too expensively but inclusive of downside insurance.
The decision concerning which strategy to choose depends on the needs
of the investor. In a risk-neutral world, all three strategies have the
same expected yield at maturity, namely the risk-free interest rate.
More mathematically speaking, the mean value or first moment of their
respective distributions of return is the same. But that’s as far as
features in common go.
The distributions of returns are a key difference. Their variance, or
its square root, the standard deviation, is a measure of risk. For both
the protective-put and the buy-write, the standard deviation is smaller
than that of the pure long position. Therefore the Sharpe ratio of both
strategies is also greater.
Outside the risk-neutral world, expected returns are not the same for
different investors. Investors who enter a buy-write might choose the
strike for the short option slightly above the level of the growth
expectations of the underlying. This way, investors can maximise their
return potential, should their view be confirmed.
Again it can now be argued that the Sharpe ratio increases. The
distribution of returns is cut off beyond the strike and therefore, in
most cases, the standard deviation gets reduced.
To recap, entering a buy-write increases the Sharpe ratio, even though one is selling an option.
Dual currency
Welfare maximisation means minimising spreads. In other words, an
investor should always aim for the simplest instruments to express a
specific view. The most transparent components are usually the most
liquid ones. Buy-writes – or the packaged version as a dual
currency deposit – are transparent and liquid.
Above money market coupons are the dominant feature of dual currency
deposits. Risk reduction and tight pricing are often neglected. As
explained above, option theory helps us to gain a better understanding
of them.
After these arguments on risk reduction, now a final word on yield enhancement.
The standard deviation or width of a distribution is not only a measure
of risk, but also of chance. The width of the distribution of returns
is the main parameter when calculating the probability for an option to
get exercised.
This width increases with the square root of time. In the words of John
C. Hull, the uncertainty increases as the square root of how far ahead
we are looking.
The consequences for the holder of a buy-write are evident. The shorter
the tenure, the more premium per time the investor gets paid for the
same probability to get exercised. This is the fair value. There is no
arbitrage.
Dual currency deposits are quoted with a per annum coupon payment or
yield. The shorter the tenure of a dual currency deposit, the greater
the coupon payment becomes. And so we have the ingredients for a
success story.
Dr Niklaus Meyer, FX Investment Products, UBS







