Last year, I had a margin account with no outstanding loan. It held $5K in CORE MMF & $28K in FCNTX (Fidelity's Contrafund). In August, with SPY @ $428, I wanted to sell a SPY $393 put. I couldn't sell a cash secured put with only $5K in CORE. So I sold (only) ONE naked put, hoping it'd never be assigned. In October, after a couple of put repairs (roll-outs) & SPY @ $369, I was assigned to buy 100 SPY @ $391 (my repaired strike price). It created $34K in margin debt. I then sold covered calls & also collected 1 dividend. In February, '23, with SPY @ $407, my $401 covered call was assigned so I was forced to sell my 100 SPY @ $401.
Over the August to February investment period, I received $1.78/share in dividends, $22/share in put/call premiums, & $10/share in capital appreciation. But, at an average margin rate of 11.5%, I paid $10/share in margin interest.
Over the 6 month period, my credits were $33.78/share, or a $3,378 gain. On a $33K start-up value, that's over 10%. But my very expensive $10/share in margin interest ate up $1,000 of my gain, leaving a $2,378 net gain, or just over 7% in net gain. Margin interest ate up about 30% of my credits.
Margin risk? I was assigned to buy SPY @ my $391 strike price when SPY traded at only $369. Although I had a few dollars in SPY put premiums in my back pocket, I was getting crunched. Still, at only $369 a share, my SPY shares (& FCNTX shares) were able to comfortably support my $34K in margin debt. But if SPY dropped further (COVID brought it down to $253 in 2020), a margin call could have been presented to me, forcing me to sell some SPY shares at an awfully low price.
