Cardog, I would expect you can't hold too much. The problem is when you are selling. When you sell, just sell in smaller blocks than what you hold.
i.e. If you hold 5,000,000 shares and want to close your position, sell in 1,000,000 increments.
That way you do not put too much selling pressure on the ASK. Always sell when there is NEWS and ALWAYS SELL @ THE ASK!
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