For a "long" position you can use a series of linear equations to estimate how much the price of an asset would need to fall for your margin level to drop to 80% (the “margin call price”).
For example:
You've just entered into a “long” BTC spot position on margin by purchasing 1 BTC with 5:1 leverage at a price of 20,000 USD. You can estimate the approximate margin call price of your purchased BTC as follows. Assume that, after purchasing the 1 BTC, your Kraken account metrics are:
- Trade Balance - 10,000 USD (assume your collateral balances are 100% composed of USD)
- Used Margin - 4,000 USD Opening Cost - 20,000 USDCurrent Margin Level - 250%.
We start by calculating what your equity would have to be for your margin level to fall to 80%:
- Since: Margin Level = Equity / Used Margin
- Then: Margin Level * Used Margin = Equity
- So: 80% * 4,000 USD = 3,200 USD.
Using the calculated equity amount (in this example, 3,200 USD), we can estimate the aggregate amount the BTC you purchased would need to decrease in value to trigger a margin call.
- Since: Equity = Trade Balance + Profit/Loss
- Then: Equity - Trade Balance = Profit/LossSo:3,200 USD - 10,000 USD = -6,800 USD
With the calculated Profit/Loss (in this example, -6,800 USD), we can approximate a “current valuation” for your spot position on margin. Keep in mind this calculation only works if you are “long” a given asset.
For a “long” spot position on margin, calculate:
- Since: Profit/Loss = Current Valuation - Opening CostThen:Profit/Loss + Opening Cost = Current Valuation
So: -6,800 USD + 20,000 USD = 13,200 USD
So (assuming your collateral balances are 100% composed of USD), for your margin level to drop to 80%, the price of BTC would have to fall to approximately 13,200 USD. You can use the equations above to estimate what the price of BTC would have to be for your margin level to fall to the margin liquidation level of 40% as well.
You can also use the following equation to calculate your margin call price for a long position: