This might not be the right board for this...
Suppose I place a sell order for 1 btc at $45k on your favourite exchange. Next, I place a buy order for 2 btc at 46k, will the exchange execute the trade?
This scenario feels pretty weird to me, I don't think it makes sense for the exchange to forbid the sell order from being submitted, but I also don't think it makes sense for it to execute the trade. What is the expected behaviour here?
That's impossible unless you have plenty of Bitcoin in your exchange account, because if you don't, you could only do one trade which is to sell your 1 Bitcoin in the price that you want, because you can't buy 1 Bitcoin if you don't have enough balance on your account, if you know what I mean. In order to buy 1 Bitcoin for let's say $40,000 you need $40,000+ at least in your account including the trading fee, and to sell your 1 Bitcoin at the same time at a certain price, you need another Bitcoin because you're making another trade at the same time.