Paper trading vs real trading: why profits vanish

Paper trading vs real trading: why simulator profits often disappear in a live account, from free fills and missing charges to lot size and margin.

25 September 2026 7 min read #basics #risk #tools

The biggest difference between paper trading vs real trading is usually not nerves. Most simulators are easier than a real broker. They give you better fills, skip the charges, or let you trade sizes and margin no real account allows. Fix those gaps first, and your paper profit gets much closer to what a real account would show.

Maybe you've seen it happen. Three months on a simulator, a win rate over 60%, then a real account with the same strategy and steady losses. People blame nerves. Often, though, the paper profits were never there.

Here are five places the gap hides, roughly in the order they cost you money. Then there's one thing no simulator can fix, including ours.

Did the simulator give you a free fill?

Some simulators let you type a price and fill you at it. Some fill a limit order the moment the last trade touches your price, as if you were first in the queue. Others fill you at the price you saw a second ago, not the price that exists now.

Each one is a small gift. Say an index option moves ₹2 in a second, and you get half a rupee better per unit on every entry and every exit. On a 75-unit lot that's ₹75 per lot per round trip. Over 200 trades it adds up to ₹15,000 of profit a real order book would never have given you.

On our desk the price field on the order ticket is only a readout. You can't type into it. Every order fills at the last traded price at the moment you place it, taken on the server. A stop is a trigger, not a promise: it closes the position at the price of the tick that reached or crossed it. If the market jumps from above your stop to well below it, you get the price it jumped to, just like a real stop-loss market order. More on that in trailing stop loss explained.

Were charges taken out of every trade?

A round trip on an NSE index option pays brokerage, STT (Securities Transaction Tax), exchange charges, SEBI fees, stamp duty and GST. Brokerage alone is ₹20 per order at most discount brokers, so ₹40 before anything else. STT on the sell leg is a percentage of the full premium turnover. On a ten-lot Bank Nifty trade the total comes to around ₹160. The full working is in what a round trip actually costs.

Charges hit hardest on the strategies that look best on a free simulator: lots of small, quick wins.

Take a scalp that caught ₹0.50 of premium on 300 units. That's ₹150 gross, and roughly ₹155 in charges. Green on a screen that ignores costs, red in a real account. A strategy made of trades like that can win 70% of the time and still lose money every month.

So ask one question about any paper record. Is it net of charges? Every statistic in this app (win rate, average win, expectancy, profit factor, drawdown) uses the figure after charges. A trade counts as a win only if it made money after paying for itself.

Could you really trade that quantity?

You can't buy seven units of a Nifty option. Derivatives trade in lots. The lot size is the fixed number of units in one contract, set by the exchange and changed from time to time. A simulator that lets you pick any quantity lets you hold sizes no real account could, usually less than one lot. So the risk looks gentler than it is.

It hides the other end too. An order bigger than the exchange's freeze quantity gets split into several orders, and each one pays its own brokerage.

Here you never type a quantity. You choose lots. The lot size comes from the exchange's own published symbol master, and an order above the freeze quantity is charged as the number of orders it would really take.

Did it lend you margin you didn't have?

Margin is the money your broker blocks to let you hold a position. Buying an option costs only the premium, which is the option's price. Selling one blocks a percentage of the underlying's notional value. On a Nifty lot that's somewhere around two lakh rupees, just to collect a few thousand in premium. We explained why in why selling an option needs so much margin.

Some simulators size short-option margin off the premium. That lets you sell ten lots on a one-lakh account. The equity curve looks amazing, right up to the day it doesn't, and you could never have held it with real money.

When this app can't get the underlying's price to work out that margin, it refuses the order. It doesn't guess.

Was the account too big to take seriously?

Some platforms hand you a crore of virtual money. A ₹5,000 loss on a crore is a rounding error. On one lakh it's 5% of everything, and it changes how you trade the next one.

It's worse when you can top up after every bad week. Then you aren't learning risk management at all.

Here every account starts at ₹1,00,000. A refill can bring a fallen balance back up to that figure, never past it. It only works when no position is open, and only a limited number of times. A winning account can't buy extra ammunition, and a losing trade can't be rescued halfway.

What does no simulator model?

Get all five right and a gap still remains.

A simulator fills at the last traded price. A real order meets a bid-ask spread (the gap between the best buyer's and best seller's price) and a queue. In a liquid at-the-money Nifty option the spread is often a tick or two. In a far strike, a thin stock, or the last minutes before expiry it can be several rupees, and a market order pays it. Real orders can also fill in parts at different prices.

This app doesn't model spread, depth or partial fills, and neither does any free simulator we know of. Treat every paper fill as a little better than you'd really get, and prefer strategies whose edge survives that.

Then there's psychology. A realistic simulator won't remove fear. But if your paper record used real charges, real lots, real margin and a realistic balance, fear is the only new thing in a live account. That's a much smaller problem than finding out with real money that the strategy never worked.

Is your strategy ready for real money?

Before you go live, open your paper record and check:

Is net P&L positive over at least 50 closed trades? With fewer, the win rate is mostly noise.
Is expectancy well above the charges per trade? Expectancy is your average profit or loss per trade, after charges. Say it's ₹30 a trade on one 75-unit lot. Pay just ₹0.50 of spread on the way in and out and that's ₹75 gone, so the edge is gone too.
What was the worst drawdown as a % of the account? Drawdown is the fall from a peak to a low. Could you sit through it with your own money without changing the rules?
Did it work with real lot sizes and real margin? If it only works at a quantity you can't trade, it doesn't work.
How much profit came from the best three trades? Take them out. If the record goes negative, you had a lottery ticket that paid out once.

The trade history page here shows net P&L, win rate, expectancy, drawdown and your largest win for any date range you pick, all net of charges, with every trade listed underneath.

Quick answers

Why do my paper profits disappear when I trade live?

Usually the simulator skipped charges, gave you easy fills, or allowed sizes and margin a real account wouldn't. Check first whether your record is net of charges.

How many paper trades should I do before going live?

At least 50 closed trades before you trust a win rate. More is better.

Does thepapertrade model the bid-ask spread?

No. It doesn't model spread, depth or partial fills.

Nothing here is investment advice, and a paper record can't promise what a real account will do.

Try it on a simulator first.

₹1,00,000, real NSE prices, and every charge in this post applied to every trade.

Start with ₹1,00,000