how to be a maker for either bid or ask orders on bitcoin exchanges? [duplicate]

Question

Using a random coin as an example, if the last price is 1.08999944 how can i chose either a buy or sell price that will be a valid 'maker' price ? Can i just bump the price by one Satoshi i.e. 1.08999945 and put a buy.. making it a maker order and take advantage of lower fee ?

Looking at various coins order books there seems to be a lot of open orders so to make a valid maker order do i need to first query the order book for open orders and then find a gap at a price i like and then place the order ?

I understand the maker is

... maker​ fee if the trade order is not matched immediately against an order already on the order book, which is ​adding liquidity​.

I'm just not sure how you know in advance of placing the order that it will not match an open order ?

Thanks fLo

Answer 1

In general, you can't know for certain.

Let's say you want to buy. You will be a maker if, and only if, your price is below the lowest price of any sell order (the Ask price) at the instant your order is placed on the exchange. If your price is above the Ask, it will be instantly executed and you are a taker. (At least, up to the extent that the open sell orders are large enough to fill it. If the sell orders at or below your price do not fill your entire order, then the rest of the order remains on the book. The exchange might charge you the taker fee only for the part that executes immediately, and the maker fee for the rest; you'd have to check their policies.)

You can check the order book and try to name a price above the current Ask. But there will always be some delay between the moment you check the book and the moment your order arrives at the exchange, and it's possible that further sell orders arrive during that window of time. So you can never be sure.

(It's possible that the exchange might have an option to only enter your order if it would be a maker, and to cancel it otherwise. You'd have to ask if they offer such a thing.)

Note that the Last price is irrelevant to all of this. It only gives the price of the last order that executed. If additional unmatched sell orders have arrived since then, it's entirely possible that the Ask price is below the Last.

If you want to sell, then everything is reversed: you are a maker if, and only if, your price is above the highest price of any buy order (the Bid price).