Yes. Although I wouldn't call it daytrading, more like intraday trading. 2 guys in our group take on enough 5-10k position of various stock to push the BP to the levels you speak of.
BTW I read that daytrader Mark Rosalbo from NJ Was Daytrading 50k-100k shares of QQQs and Spiders, the same article said that he made 1,5 millions dollar last year.. part of the article: Mark Rosalbo trades barefoot. That is just one of the benefits of trading from his suburban New Jersey home. He has an office in his attic equipped with multiple flat-screen monitors that he uses to place trades and analyze markets. The benefit, he says, is time spent with his family. Not being the typical type A personality, he doubts he would thrive on the trading floor. But upstairs, Rosalbo does just fine. The quiet atmosphere he created belies that on any given day Rosalbo can account for as much as 30% of the off-hour volume in the QQQ, the ... www.futuresmag.com/library/2003/09/03_0903soundoff.pdf
I have over 70 million in buying power between three accounts. For daytrading however, I doubt I've ever had more than $3M on at a time. Now, if I wanted to go out with a bang, I could have some fun unleashing that kind of capital all at once. Would really freak out a few risk monitoring guys I'm sure.
I would think that someone swinging that kind of buying power in equities would be forced to either trade hugely liquid issues (such as the QQQQs), or would be focused on a basket trading approach in order to cover sector moves (someone already more or less mentioned this).
Two intraday / daytraders of fame who run hedge funds with about 1 billion each James Simons - Renaissance Technologies Toby Crabel - Crabel Capital Management
"Anyone think it is possible to day trade stocks (not futures and close out positions by end of day) with buying power in excess of $20 million?" The following is certainly reasonable: (note that each block of 20k could be replaced with (4) 5k blocks - making 20 trades or 40 round trip.) 20,000 shares GOOG @ $285 = $5,700,000 20,000 shares SHLD @ $155 = $3,100,000 20,000 shares UTX @ $107 = $2,140,000 20,000 shares CME @ $230 = $2,300,000 20,000 shares TOL @ $96 = $1,920,000 Total: $15,160,000 One can certainly expand on this. Now, would one want to trade in this fashion? I would certainly find it more useful to build positions in a variety of stocks over a certain amount of time.