The OP and other higher volume traders should take a look at www.efficientexecutions.com over IB.
For someone like DeeDeeTwo who trades 4 million shares a month:
IB costs .001988 per share or $7,950 per month on 4 million shares
Efficient Executions costs .001275 per share or $3,100 per month on 4 million shares
That is a savings of almost $5k a month. The savings is really even larger than that because of IB's $0.70 minimum per trade.
For someone like DeeDeeTwo who trades 4 million shares a month:
IB costs .001988 per share or $7,950 per month on 4 million shares
Efficient Executions costs .001275 per share or $3,100 per month on 4 million shares
That is a savings of almost $5k a month. The savings is really even larger than that because of IB's $0.70 minimum per trade.