Let’s say you want to buy 100 shares of Acme Corp. at $50 per share, but you want to borrow half of the $5,000 purchase price from your broker, who requires you to keep at least a 25% maintenance margin in the account to cover any unexpected losses.
The margin call price then is: 50* ((1-.5)/(1-.25)), or 50* (.5/.75), or 33.33
This means that if the price of Acme stock falls below $33.33, you’ll need to add funds or deal with a margin call.
Again, receiving a margin call is (generally) far from the worst thing that can happen to an investor. Although investing with borrowed money can be quite lucrative, it can also go wrong quickly. People who buy stocks on margin should be aware of the potential downsides and manage risks accordingly.