Quote from TonySanDiego:
Getting back in to doing opening orders.
Today, 17 fills, I tightened up my entry envelopes.
I can hardly wait for the day I have 14 losers and 3 winners.
:eek:
Tony,
Do keep that risk element in the front of your mind at all times.
These are some of the questions I ask myself: (I'll use your numbers in my example).
Can you afford to get a 3 sigma fill day? (I'm guessing that might be around 45 fills....a really rough guess on my part). Three days ago was one of those for me. Now, what if 40 of those go against you? How do you stop out and how much slippage will you expect? Worst case, you might assume that you average a .15 loser on each stock traded (winners and losers). That'd be a negative $6 day. So doing 100 shares of each would cause a $600 hit to your P&L, and 1000 shares, $6,000. Size accordingly.
Also, if your approach results in a 60% system (I'm guessing again), then also consider that it's not outside of "normal" bounds to have five or six losing days in a row. Say that a trader's 1 sigma day is 20 fills, with 13 losers. Again, I'm speculating that the 1 sigma average trade is -0.07. That would be a ($.91) day. For five consecutive days, you'd be looking at a ($4.55) drawdown. Again, at 100 shares that's only $455, but at 1000 shares, that's $4,550 against your P&L.
My advice would be to size accordingly, and don't give up when you see those extreme events. The same is true when you see those five winning days in a row....
Obviously, this is a subject near and dear to my heart. I, as well as many traders that I know, run automated programs that do opens on over 100 stocks, in some cases, many times that amount. The approach is a good one, but I'm always thinking about those points above.