Today's trading summary:

1. I was such an idiot this morning. I said I should try to stay focused, but with SPCX's lock-up expiration tonight and my model showing a very high probability of a QQQ rebound, I thought I should add to my positions. I decided not to add SPCX, though. The overnight session was looking pretty good shortly after it opened at 6 a.m., so I added MU and SOXL. They weakened again later, and after reflecting on it, I cut my losses.

2. To address my lack of focus, I doubled my QQQ position later today because I expected the broader market to rebound. That trade was okay; my cost basis is 706. Going forward, I should stick to QQQ/SPY plus just one stock I like best. Index ETFs help protect the floor of my returns and make my trades more predictable, while individual stocks raise the ceiling and offer more explosive upside. But it should only be an index ETF plus one individual stock.

3. For this QQQ rebound, I see a high of 728. Then it may retest the lows. After a run-up, some weaker names could be candidates for shorting—for example, memory stocks. But I need to check their earnings reports over the next few days: if results are merely average, they could be short candidates, but if they beat expectations, I shouldn't short them casually. Going forward, I need to follow through on what I know.