# How should Aggressive Limit Orders be Processed in a Limit Order Book

I am a little confused about how orders get processed in a limit order book, hope to get a better understanding with this post.

If we start off with an order book

Asks:
SELL 2 units at 300
SELL 2 units at 200
SELL 1 units at 100

Bids:


and a user places a new limit order which causes his account balance to decrease by $400 (2x200 = $400),

New Order: BUY 2 units at 200


Is the resulting order book supposed to be

## Order book #1

Asks:
SELL 2 units at 300
SELL 1 units at 200

Bids:


because his order of quantity 2 first matches with 1 units at 100 then matches 1 units at 200

or should the resulting order book be

## Order book #2

Asks:
SELL 2 units at 300
SELL 0.5 units at 200

Bids: