Well, that is an interesting question. The CME believes during times of stress and volatility, that raising margin reduces speculation. I agree. That should help calm markets with less leverage. Maybe not on day 1 but overall. During those times you are asking about, I was an option market maker with market maker margin. There was no Portfolio margin. Increasing over-night requirements with Reg-T margin is only important with a concentrated portfolio or short positions on very volatile illiquid stocks. As a MM, my margin was based on RBH-Risk-based haircut. Similar to PM but less limiting as I was not confined to 1X the requirement. My clearing firm was GSEC. Margin and risk are different, same with a PMA today. As long as I had little risk of going into their money, they never cared how big I got. They did shock up/down 50% on non-index positions and would often ask traders to cut back when that number exceeds their limits. I found this story a little funny at the time. This was from the mid 90's. A MM in the AAPL crowd with a $50K account was short too many puts. He had no margin call. The floor guy that ran SLK (Before GSEC bought them) asked the trader, " are you comfortable with your downside because we are not." He said "yes". the SLK guy said, do you understand what I'm asking you to do-reduce you short put count? He said "yes". the next morning, the SLK guy came back over about 9am. Said, you sold 10 puts yesterday. I thought you understood? He yes, I'll take care of it today. the next morning, the SLK guy came back. He said to him, yesterday we had an understanding, Same with the day before. Instead of reducing, you sold 10 puts. the next day, you sold 15-your done. SLK withdrew their clearing guarantee, alerted the exchange and an exchange employee took his trading badge away. He never came back. This is a game of trust. Your clearing firm has to trust you. Your broker needs to trust you. If they don't, this can happen to anyone. I have seen it on the retail side too.
%% Good discretion+ the downtrend is your friend.Actually i dont hate TSLA; i just hate him attacking short sellers , customer service so bad WSJ has to publish that LOL,+ SEC $40,000,000 fine ............................................................................................,
And that's the good thing about occasional leverage,occasional 3X ETFs;its possible to makemore than11O%.. Many data services had SQQQ making 333%, one week LOL.That was stock split/error, but my point still stands. NOT a prediction, but I will be surprised if SQQQ does not do better than 150.777% by NOV. NOT saying I would catch all the move if it did,LOL.,