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Calculating Margins

Placing trades can feel overwhelming if you don’t understand the importance of calculating margin. A margin allows you to buy securities by borrowing money. The margin is the difference between the market value of a stock and the loan amount. Check out the sections below to see how TD offers helpful tips to understand margin calculations so you can better predict profits and losses and become a more confident, skilled investor.

Learn how to calculate margin

Collapse Calculating Margin Requirements

To calculate the margin required for a long stock purchase, multiply the number of shares X the price X the margin rate. The margin requirement for a short sale is the regular margin requirement plus 100% of the value of the security.

Margin Requirement = shares x price x margin rate percentage


Long Stock

Purchase 1,000 shares of a stock at $50 with margin rate of 30%. The margin requirement would be:

1,000 shares x $50 x 30% margin rate = $15,000

This is the minimum required amount of cash or excess margin that must be in the account before a buy order can be entered.

Since 30% is the margin rate, TD Direct Investing is lending the account holder 70% of the trade value.

Maximum loan value is 1,000 shares x $50 x 70% = $35,000

Short Stock

Short sell 500 shares of a 50% marginable stock priced at $10.00. The margin requirement is 150%. Note: 100% of the margin requirement is generated from the sale of the security. Therefore, the additional initial margin requirement is 50%, the same amount required in order to accept the trade if you were purchasing the stock.

500 shares x $10.00 x 50% = $2,500

The total margin requirement to hold the position, including the 100% of the proceeds from the short sell, is calculated as follows:

500 share x 10.00 x 150% = $7,500

(Note: TD Direct Investing does not pay interest on the cash proceeds of the short sale.)

Expand Maintaining Adequate Margin

Expand Calculating Maximum Trade Size from Margin Excess

Expand Calculating Maximum Trade Value at Different Margin
      Rates for $5,000 Excess Margin

Expand Calculating Net Margin Position on Electronic Brokerage Services