We’ve decided not to support market orders because the spreads on options contracts are typically much larger than stocks, and because options contracts have much less liquidity in the market. Placing limit orders will give your order a better chance of being executed at the price you want. This way, you’ll know how much you’re going to pay to buy a contract. For the same reason, we also don’t support stop orders.
You can place Good-til-Canceled or Good-for-Day orders. Your app’s default setting is Good-for-Day, but if you’d like to enter a Good-til-Canceled order, you can simply tap the clock icon and select Never Expires when you place your order.