Oh! I realize I was thinking about a specific type of option, namely selling covered calls. In order to do that, you have to own 100 shares since they are sold in 100 share blocks.
I forgot that you could buy or sell options on stocks you don’t own. Not something I plan on doing, but am interested in selling covered calls of VTI per the book shared on this forum. Need to read it again and do paper trades first.
Ah, yeah, you left that part out. ;-)
So selling a call is accepting money from someone to give them the right to buy 100 shares of whatever at a specified price in a specified timeframe. In your case, VTI.
Options *can* expire worthless. If you sell a call option on VTI at a strike price of $285 for June 21st, you can collect $1 for that option (the call option is trading at 1 cent). If VTI never trades above $285 between now and then, then the person who paid you $1 for that option will just never exercise it. You keep the $1, and it apparently doesn't matter if you owned the 100 shares of VTI or not.
But if they do exercise the option, then somehow someone has to deliver 100 shares to them for $28,500. If you're selling the option and own those 100 shares VTI, then that is having the stock called away from you. That's a risk you're taking by selling those covered calls, because you're giving away (well, selling) any upside over $285 between now and June 21st. You end up selling the shares to the person who bought the call option for $285, but those shares might be worth $287 on the open market. It does happen from time to time, and it's the main risk to the strategy you're considering.
If you don't own the underlying shares, then I think that's called naked selling, and you may need to get approved for a margin account to do that. Because worst case, if the call option you sell gets exercised, you have to buy the shares on the open market, maybe for $287 a share, then deliver them to the option buyer at $285 a share, and you're $200 in the hole (i.e., in debt to your broker) that you have to cover somehow. Your broker wants to know that you'll pay them back!
Another choice is if the option you sell might get exercised (because VTI is getting close to $285 a share in this example), then you can buy it back. But the price you pay to do that might be more than the price you sold it for earlier. Then you're off the hook to deliver the 100 shares VTI, but you lost money in the process.
Oh, and options, like any other financial instrument, have trading costs. Bid / ask spreads and commissions are at least two things that I think create trading costs for options, just like they do for stocks.
It's a zillion times more complicated than that, and since I don't trade options I'm not 100% sure of the above. Maybe someone who trades options will correct / clarify / amplify.
Personally I think betting on the future prices of stock is very difficult, so I don't even try. But some folks here do.