Why would anyone want to sell a put, when they can buy a call, and have less downside with the same upside? Am I not understanding something?

Couple reasons. When volatility goes up, options get expensive. Spreads grow too. You seem to know the basics, so if you're just trying to trade premium, between the spreads and the delta, you may find it somewhat difficult to sell for a profit even after a considerable gain. Can sell the put and let it expire worthless.

As spin said. if you're willing to buy a stock at 98, not just trade the option, but if you believe it may hit 98 and not much lower....you don't think its on its way down to 90...., why not sell the option to make some premium rather than setting a limit order to purchase at 98.

I was looking at Netflix...the $80 march put is roughly $1.20. Thats a 1.5% return in 3 months. Rather safe investment. May meet your objectives. You can also buy the $50 put for 20 cents....that takes your risk from $80 / share to $30 / share. Now you just doubled your return. $1 for every 30 risked.....a little over 3 % return in 3 months....on track to 12% in a year.

One time i was looking at a facebook call spread. This is back during the correction, when it moved its way to just above 90 / share. An 88/88.5 call spread cost $0.45. That was nearly guaranteed...very low risk. 11% return. Realistically, to close the position, i'd have to sell for $0.49.....but hey, a little over 9% in 1 week...

But now commission....each leg has the standard broker commission, and also the option commission. I found i had to spend $1700 just to break even. Little risk, but still risk. It wasn't worth it. Also, you risk getting assigned by someone who shorted and bought the option as a hedge....if you don't have the money to cover it, your broker gets a bit upset. I already got the, if it happens again, we're downgrading your account, call.

A put spread on the other hand. Sell a 88.5 and buy an 88. Same thing....get a $0.05 credit, but risk $0.50. So you actually are risking $0.45. Difference is, you don't worry about closing, you just let it expire worthless. Commissions just got cut in half.

As someone who has sold a lot of puts and bought relatively few calls, I can say there are a lot of reasons.

Spin gave you one good example. You can sell a put to buy a stock at a discount or, if the stock ends up over the strike price, make a profit without ever buying the stock.

Another thing to remember is that options are wasting assets. Unless there is a significant change in the price of the underlying security, option prices on the security go down as time passes. Option buyers tend to have a lot of small losses and a few big gains. Option sellers tend to have a lot of small gains and a few large losses.

A lot of option traders use spreads to limit potential losses, and may adjust those spreads prior to expiration. When an option is sold as part of a spread potential losses and potential gains are both limited.

Most option traders want to buy options when they think implied volatility is too low, but would prefer to sell options when they think implied volatility is too high.

Also remember that if you buy an option and it expires worthless, you have lost 100% of your investment. Game over. If you sell a put and are assigned you end up owning the underlying security, which may (or may not) go up in the future. It is true that the put seller can easily have a much larger unrealized loss, but probably much less than 100% of his total investment (including the cost of buying the stock).To give you one example, I sold some puts on a stock and was assigned, sold more puts on the stock at a lower strike price and was assigned again, but my faith in the company was rewarded and I ended up selling the stock at three to four times what I paid for it.

I am not advocating selling puts to anyone else. I am just saying that it worked well for me.

People in the market have different objectives and risk tolerance.

Suppose I own a stock XYZ at 100, I'm neutral to mildly bullish (2 out of 3 scenarios benefit you), I'm willing to give the stock up at 105 plus some add'l income. I sell a 105 covered call for 2 pts, lowering my cost basis to 98. If XYZ rises above 105, I net 7 points. If at 100 at expiration, I keep the 2 points and repeat the process.

Suppose I don't own the stock now but I'm willing to own it at 98. I could sell the 105 put for 7 points. If 100 at expiration, I buy the stock for 105 but given that I received a credit of 7 points, my cost is 98. At 100, I'm up 2 points. If instead, the stock has risen above 105, at expiration, the put expires worthless and I have made 7 points.

By now, you should grasp that a naked put is synthetically equal to a covered call and the option decay goes into your pocket. Now if I'm not comfortable with stock ownership or I'm bearish, both of these are not a good idea.

Call buying requires that you be right in timing and direction (only one scenario favors you). Decay is your enemy. Lower probability of a large reward, higher probability of a loss. If you are good at this, you do quite nicely. If not, time decay kills you.

In terms of risk/reward, CCs and NPs are lousy. You eat like a bird and sh*t like an elephant.