Good description of a covered call here: https://tastytrade.com/learn/options/covered-call/

You can sell 1 options contract per 100 shares.

Using a price of $300 per share of MSTR. Let’s say you have 400 shares of MSTR, valued at $120,000 currently.

I typically try to sell around a 10 Delta covered call. The 10 Delta means that at the moment the market is assigning about a 10% probability of that specific contract being in-the-money at expiration. In-the-money means that the option is executable and, in the context of a covered call, your shares could be called away from you.

You have to decide on a couple things, 1) the expiration date and 2) the strike price.

At the moment (Feb 21), a single contract for a 410 call expiring on 3/14 (21 days) is a net credit of $2.75/contract. Someone is willing to pay me $275 for the option to buy my 100 shares from me at $410/share on or before 3/14.

With 400 shares I would be able to sell 4 contracts and get $1,100 deposited into the account as cash (400*2.75). 

If I were to make the trade above, I could collect $1,100 and buy 3 additional shares of MSTR if I wanted or put that money into a BTC ETF, etc, etc.

Here are the scenarios are that could happen:

1. MSTR stays below 410 by expiration. I get to keep the $1,100 and am able to sell more options for the next month, collecting additional premium.
2. MSTR goes above 410. I get to keep the $1,100 but miss out on any additional gains beyond the increase in the stock price from the current $300 to $410. You’d get $164,000 in the account (400 shares * $410) plus the $1,100. Your breakeven point is a stock price 412.75 (410+2.75 collected as premium). You miss out on any gains beyond 412.75. If you do NOT want your shares sold at 410, then you can choose to buy the call back (buy-to-close is the term) (which you would pay more than $1,100 to do!) and then could sell another call at a later expiration to collect enough premium to pay for the buy-to-close plus collect some net credit. This is called rolling the option.
3. MSTR drops way down and you want to sell MSTR. The 400 shares are locked in this case and you would have to buy-to-close the options first before you are allowed to sell the shares. However, this is usually really cheap to do since the price has dropped way below what the strike price is.

For the above example, we collected $1,100 on $120,000 worth of MSTR, about 0.92% in 21 days. If we are able to collect that much every month for a year, that would be $13,200 collected in premiums, or an additional 11% profit received.

If MSTR stays at $300, then that is an additional 44 shares of MSTR purchased over the course of a year.

The 300 price to strike price of 410 is an increase of 36.7%. If you changed from 410, down to 370, that would collect a premium of 5.00. So $2000 premium collected per 4 contracts sold. This would be about 1.7% premium collected per month or $24,000 per year. 20% per year.

In my opinion, this is a great way to collect extra money in an account that you are limited with how much you can add per year. Imagine doing this in a 401k? That basically doubles what your own contribution can be. The tax free or deferred accounts are also great for this strategy because there are otherwise short term capital gains incurred with the premiums collected.

More volatile stocks have higher options premiums. Saylor is incentivized to keep volatility of MSTR high and given how it tends to trade along with BTC, it should maintain higher volatility for quite awhile.