It’s one thing to trade on Think or Swim (ToS) by TD Ameritrade and use the default ten lots on something like SPY weeklies or AAPL weeklies that often times cost less that $1/contract. What becomes more difficult though is trading expensive option contracts with the default quantities that the platform loads. When bumping up to something like a TSLA, an at the money options contract can cost north of $1000. A default ten lot is a sizable position regardless of your account value.
It’s important to note that when you get into the correct settings menu the default quantity will be what changes the shortcut buttons that show up next to or beneath your active trader buttons. The increment on the other hand will change how many contracts are added or removed by clicking the plus and minus buttons.