Though directed to ST Sir, will just add some nibbles of info that I have.
On an interview, Anton Kreil said he allocated 60% to equities, 25% forex, 10% commodities and 5% for intraday opportunities. Also, some big retail traders trade just FX due to 24 hour trading and high liquidity. One of my known persons (prof) trades ~$20 mn globally on Indices (including SGX Nifty), Commodities and Forex, I have seen him do 2 hour trades (taken and covered during the classroom session) to 2 month trades without any specific plan on how much to allocate where, just looking at the opportunity and exploiting it. Summarily, I think it will become difficult to focus on just one instrument, one strategy and one geography/market if you are planning to set-up a hedge fund or trade ~50 L - 1 cr as retail trader.
In fact, I asked a similarly intended question just yesterday, but in terms of the max # of NF shares seniors have seen as being traded by Indian retail traders.