Good question, and if I had Ameritrade or someone else with a flat rate regardless of the share quantity I'd do just that.

I'm with Fidelity and hold EDIG in a brokerage acct and an IRA.

In the IRA, 50K all in one order is $253.00. 10K at a time is $53.00 each so $265.00, but if my orders fill from .10 thru .0106 it's a mute point.

I have had trouble getting 50K to fill in the same day once or twice.