Since the game of options based on volatility and volatility can be dramically different at small price changes. I would guess most serious traders use limit orders.
I cannot remember the last time I every put in a market order. I alwsays do limit orders and where I place it depends on the market.
For SPX and OEX/XEO I usually start right in the middle and shave $0.5 to $0.10 as needed or more in some cases. For spreads of $0.05/$0.10 I usually go right at the appropriate bid or ask but will occasionally try and sell at the ask and buy at the bid
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