Exactly. Put a limit sell order in for $4.00 or $5.00 All or None (AON) good until cancelled (GTC). When you decide to sell, open your order and make changes.
By the way, when you sell quantities that large, it's a good idea to sell them in smaller blocks. Say your target price is .50 - put a block of 250,000 on the ask at .40, another at .45, .50, .65, etc., so as not to kill the momentum. You pay more in fees, but you should make more overall. If people start stacking the ask with millions of shares, it kills the momentum, the share price is likely to plummet, and there's a good chance you won't get your price (as we've seen with the trading here lately - Ram has pointed out the ask blocks several times now during the discussions surrounding MMs and shorting).
Also, if you don't use AON, your order may be broken up into several orders, but you still just pay for one trade.
