Penson seems to now be really enforcing FNRA rules. Does anyone have a link that would clarify these rules? Example 1: If you have 10k shares of a stock, sell 5k, buy back 5k, then sell another 5k, if that is viewed as you sold the remaining of the 10k shares (FIFO basis), or is that viewed that you have resold the first 5k shares (LIFO basis)? Example 2: If I bought 1k shares more (now totalling 11k), then sell 1k shares, can I keep doing this the whole day so long as I started the day with enough day trading power to buy then sell 1k shares? Or do we view it as if you are selling from the 10k shares and causing FNRA problems?