In the US, Reg T requires at least 50% initial margin; other markets differ.
Typically 25–30%, depending on the broker.
Margin Call Price
US$66.67
A 33.3% drop from US$100.00 triggers a margin call.
Position Value
US$50,000
Borrowed Funds
US$25,000
Leverage
2.00x
Margin Cushion
US$12,500
How it works
You are buying US$50,000 of stock, putting up US$25,000 of your own cash and borrowing US$25,000 from your broker. As the price falls, your equity shrinks while the debt stays fixed. If the price reaches US$66.67, your equity falls to the 25% maintenance level and the broker issues a margin call — a demand to add cash or sell.