Why is AT PnL different from M2M?

The short answer

You may see a few different profit or loss numbers on the Positions screen: M2M, PnL, AT PnL and AT PnL Live. They can differ for two separate reasons: they measure different things, and they come from different places.

M2M and PnL come straight from your broker. They are whatever the broker reports.
AT PnL is profit or loss that our own system calculates, using live prices.
AT PnL Live is a live estimate that keeps ticking with the market. It uses a different method again, so it too can differ a little.

M2M and PnL measure different things

This is the part that surprises most people, so it is worth being clear about.

M2M is today’s profit or loss. For a position you are carrying from an earlier day, it is measured from yesterday’s closing price.
PnL is your total profit or loss on that position, measured from the price you actually bought or sold at.

An example. You buy an option at ₹10. It closes that day at ₹12. The next day it is trading at ₹20.

Number	Value	Why
PnL	₹10	₹20 minus your buy price of ₹10
M2M	₹8	₹20 minus yesterday’s close of ₹12

So on an overnight position the two numbers should not match.

PnL is the figure that matches the profit or loss shown on your broker’s own terminal (often labelled Gain/Loss or P&L). M2M is only the day’s part of it. So if your broker terminal shows a profit but our M2M shows a small loss, both are correct — compare the broker’s figure with our PnL column, not M2M.

For a position you opened today, there is no previous day to measure from — so M2M and PnL are the same number. That is correct, not a mistake.

When M2M looks the same as PnL

If you are carrying a position from an earlier day and M2M is showing exactly the same value as PnL, that number is not telling you today’s change.

This happens because some brokers send us only one profit or loss figure in their position data, with no separate day value. We are improving how this is shown so that M2M always means today’s change, whichever broker the account belongs to.

If you see this, you can rely on PnL and AT PnL for your total profit or loss on the position. Please do report it to us as well — it helps us prioritise which brokers to improve first.

Why we calculate our own value

We calculate AT PnL because the profit or loss we receive from some brokers has problems:

Some brokers send delayed PnL.
Some brokers do not send PnL in the position data at all.

So we work out our own value. To do this, our system uses:

your position’s average buy price and average sell price,
the overnight quantity carried from the previous day,
the live price of the stock or derivative, and
the fields and formula the broker provides for working out profit and loss.

Why the two can differ

Because AT PnL and the broker’s M2M are worked out in different ways, small differences are normal.

Sometimes the data the broker sends is not enough to match their figure exactly. This is more common for overnight derivative positions, where:

the data the broker sends can be inaccurate or incomplete, or
the broker does not publish the exact formula they use.

In those cases our calculated value can differ a little from the value on the broker’s own screen. The differences are usually small.

What to do if a value looks wrong

This calculation is still in BETA. If you see a profit or loss value that does not look right, please report it to us so we can check it and fix it. Share the account, the symbol, and what you expected — that helps us find the cause quickly.

You can reach us from the Contact page.

When this happens