If you click the Flatten button, a confirmation window will appear asking you to confirm that you would like to flatten your current position, effectively zeroing out the position at the market. What does the fleshy bulb do in don’t starve? don't starve fleshy bulb uses.

What is flatten in thinkorswim?

Flatten will close any open position for the current symbol and cancel all working orders.

What does it mean to flatten your position?

Unlike stocks, you can sell futures without making a previous purchase. However, you cannot realize a profit in futures trading until you “flatten” your position – placing an order for the same quantity on the opposite side of the market.