To begin, I am no experienced trader. I never got involved in the stock market until 2014-2015. I am also close to retirement age. Through luck and leveraging using margin loan my stock portfolio grew ~$1.5M in the last seven months. Here is the situation. IB portfolio margin account: Portfolio snapshot Net Asset Value: $2,903,623.05 Stocks: Only three positions total value $4,801,070.08 stock A: value $249,788, cost basis $18,326, long stock B: value $125,600, cost basis $125,100, short stock C: value $4,428,000, cost basis $3,128,220, short/long (short/long indicates the capital gain category) Cash(margin loan): -$1,897,261.15 Accruals: -$185.88 Initial Margin: $1,498,297.58 Maintenance Margin: $1,413,853.34 Available Funds: $1,404,780.19 Excess Liquidity: $1,489,769.72 Buying Power: $9,365,201.27 Special Memorandum Account: $0 Withdrawable Cash: $1,377,605.47 Withdrawable Cash Without Borrowing: $0 Question: How much a hit the portfolio can take before I get a margin call if there is a downturn. The loan to asset ratio is 39.5%. It is too high I think. I'd like to reduce it by cashing in on Stock C to pay off some margin loans although the upside of it still looks good. Because of position concentration I think IB imposes higher maintenance margin requirement on the portfolio margin account than the Reg-T margin account I previously held. I should add I want to liquidate stock B very soon, perhaps in weeks. Stock A should be reasonably stable. We've had it since after the crash in 2008. Stock C we held even longer, since 2002. It took off only two years ago. I made the profit mostly on stock C through the use of margin loans. Our other fixed and liquid assets outside of this is ~$2.7M I don't think we are worried too much about retirement. But it is not relevant to the question at hand. Advice is appreciated.