Leveraged Trading and Backtesting on VIOP: Margin, Settlement, Expiry

VIOP, the Derivatives Market of Borsa Istanbul, trades futures on indices, stocks, currencies and commodities. Unlike a stock, a position is opened with margin, so it is leveraged, which enlarges both opportunity and risk. This article explains VIOP-specific concepts and the mistakes made when backtesting this market. For regular BIST stock backtests see how to backtest on BIST.

This article is educational and not investment advice. Contract specifications, margin amounts and rules can change; confirm current details with the exchange and your broker. Leveraged trading can lose all of your margin.

What sets VIOP apart from stocks

• Margin: you do not pay the full contract value; you post a margin. The margin rate varies by contract and period.
• Contract multiplier: profit/loss is the price difference times the contract multiplier times the number of contracts. A backtest that gets the multiplier wrong is off by multiples.
• Daily settlement: positions are marked to market every day; profit and loss hit the account daily. If margin falls below the required level you must top it up (margin call).
• Expiry: contracts end on a set date. To keep the same exposure you roll to the next contract as expiry approaches, which means two extra trades and a price difference.
• Long and short: shorting, restricted in stocks, is natural in futures. That makes strategies two-sided and adds risk.

A simple P&L and margin calculation

All values below are purely hypothetical (see the contract specification for the real multiplier, tick and margin):

multiplier = 10.0          # hypothetical contract multiplier (TRY / point)
margin_per_contract = 8000 # hypothetical margin (TRY / contract)
equity = 100_000           # TRY

entry, price_now = 10_000.0, 9_900.0   # index points
contracts = 5

notional = entry * multiplier * contracts
pnl = (price_now - entry) * multiplier * contracts      # long position
margin_used = margin_per_contract * contracts

print(f"Position value: {notional:,.0f} TRY  (effective leverage {notional / equity:.1f}x)")
print(f"Daily settlement loss: {pnl:,.0f} TRY  -> remaining equity {equity + pnl:,.0f} TRY")
print(f"Margin used: {margin_used:,.0f} TRY  ({margin_used / (equity + pnl):.0%} of equity)")

In this example a mere 1% index drop books a 5,000 TRY loss and 5% of equity is gone; effective leverage is about 5x. On a day the index falls 5%, the loss reaches a quarter of your equity. Size the position by the loss you accept, not by the margin limit.

Common VIOP backtesting mistakes

1. Stitching continuous-contract data naively: price gaps between expiries (contango/backwardation) create artificial jumps on roll days. Stitching without adjustment produces fake profit and loss.
2. Skipping the multiplier and tick size: mixing point returns with TRY returns.
3. Ignoring daily settlement: until a position closes, P&L looks "on paper", yet margin and call calculations run every day. Rare but violent moves can force-close the strategy through a margin call.
4. Incomplete costs: add commission and exchange fees together with roll costs. The commissions and slippage article shows the calculation step by step.
5. Liquidity assumptions: near-expiry index contracts are liquid; far-dated and single-stock contracts can have much wider spreads and slippage.
6. Survivorship and period bias: a test covering only a bull run gives dangerous confidence when combined with leverage. Cover different regimes (see survivorship bias and period selection).

If you use signals

For any signal shared for leveraged VIOP trades, check: which contract and expiry, how many contracts, the stop level and the roll plan. Without net (after-cost) results and a timestamped record, a signal cannot be verified. For the general checklist see the signals section in the crypto futures article and the guide to reading signals.

A safer roadmap

1. Test the strategy first without leverage (on stock or index returns).
2. Retest with VIOP costs, multiplier, roll and daily settlement.
3. Run it on live data in the paper (simulated) stage with a small number of contracts (guide).
4. Apply the principles in leverage and liquidation risk; with real capital start only with an amount you can afford to lose.

This article is educational and not investment advice. Past results do not guarantee future performance; leveraged trading can lose all of your capital.