Today the SEC margin rule requires 2000$ for margin and all brokers require at least 4000$ for a margin account. With the new SEC margin rule requirement of 25.000$ I expect brokers to require 50.000$ in account to give you access to margin and shorting. With the new 4x margin it makes a lot of sense not to give 4x margin at the new limit required by the SEC (25.000$). Too big risk of enormous loss. 25.000$ is 100.000$ in buying power. If you use all buying power you hold 100.000$ in stocks. If your stocks lose 1% you drop below the new SEC limit for margin and your account becomes a cash account. You are now holding 99.000$ in stock with a buying power of 24.750$. Will cause margin call to cover the missing 75.000$ you owe your broker. IB wouldn't even do a margin call. They would liquidate and ask you to send the missing 50.000$. You just lost 75.000$ or 300% because of a 1% drop in the value of your stocks. A death trap. They won't give you margin and shorting with just 25.000$ with new SEC rules.