This is a more difficult topic, but one which demands attention from all investors, not just option traders. Much ink has been spilled on the topic of portfolio diversification, wherein it is said that those who trade in multiple different underlyings, can be said to “spread off their risk”. In other words, rather than having all of your eggs in one basket, say, by just investing in Google, you try to invest in multiple symbols at the same time, so that the risk of one symbol is spread off by investing many symbols. But does this really work?
Part of Tim’s shorting strategy relies on investing on many underlyings at once (sometimes), and I assume investing small amounts like $1-2000 at a time so that the gap losses, when they happen, will be small (intraday losses are minimal because of tight stops – when they are employed). However, as we shall see, this is partially a false sense of security.
We see in one study that up to an n of 30, increasing the number of instruments in one’s portfolio does indeed reduce volatility and risk. Standard deviation (risk) initially might be 49% with one instrument, but only 20.9% (a reduction of about 60% of the risk) with up to 30 instruments. However, beyond 30 there are limited returns.