How Leverage Magnifies Gains and Losses

Leverage means controlling a position larger than the money committed to it, so every percentage move in the asset becomes a larger percentage move in the trader's equity. At a leverage ratio of L, a price change is multiplied roughly L times, in both directions, minus the cost of the borrowed part; a fall of 1/L in the asset's price (a rise, for a short position) erases the equity entirely.

Key takeaways

Return on equity is L × the asset's return − (L − 1) × the borrowing rate, so leverage also raises the return the asset must earn to break even.
The asset move that wipes out equity is 1/L: 50% at 2:1, 5% at 20:1 and 2% at 50:1. Over the ten years to October 13, 2026, the S&P 500 closed down 2% or more on 87 days.
US rules set the ceilings: 50% initial margin on stocks (Regulation T), 25% maintenance (FINRA Rule 4210), and retail forex deposits of at least 2% on major pairs or 5% on others (CFTC).
Volatility drag grows with the square of leverage: at the S&P 500's 18.1% annualized volatility, about 1.6% a year unleveraged, 6.6% at 2x and 14.8% at 3x.
Daily-reset leveraged ETFs hit their multiple only day by day; in the ten-day example below, the index gains 0.81% and the 2x fund loses 0.79%.

The arithmetic behind leverage

The leverage ratio is the value of the position divided by the trader's own equity in it. A $20,000 stock position bought with $10,000 of cash and a $10,000 loan has a ratio of 2:1. A futures contract or a forex trade works the same way, except that the "loan" is implicit: the trader posts a deposit and carries the full price exposure.

Return on equity = L × R − (L − 1) × c
Asset move that erases equity = 1 / L (a fall for a long, a rise for a short)
Break-even asset return = (L − 1) × c / L

L = position value ÷ equity (1 = no leverage)
R = the asset's return over the period
c = borrowing or financing cost over the same period

The first line holds for a position kept for one period without additions or withdrawals. The cost term matters most when returns are small: at 2:1 with an 8% annual borrowing rate, the asset has to rise 4% in a year just to break even.

How small a move does the damage

The table applies the formulas at leverage levels a retail trader meets, ignoring costs. The last column counts how often the S&P 500 fell at least that far from one close to the next, using FRED's daily S&P 500 series for the 2,511 trading days from October 2016 to October 13, 2026.

Leverage	Equity as share of position	Equity change on a 1% asset move	Asset fall that erases equity	S&P 500 daily falls that large, 2016–2026	Where it appears
1:1	100%	1%	100%	0	Cash purchase
2:1	50%	2%	50%	0	Stocks at the Reg T initial margin
3:1	33.3%	3%	33.3%	0	Older 3x daily ETFs (per day)
5:1	20%	5%	20%	0	EU cap on single-stock CFDs
10:1	10%	10%	10%	1	Futures margined at 10% of notional
20:1	5%	20%	5%	6	US retail forex, non-major pairs
50:1	2%	50%	2%	87	US retail forex, major pairs

The worst close-to-close day was −12.0% on March 16, 2020. Intraday swings are larger than closing moves, and a margin call or liquidation normally closes a position well before equity reaches zero. Forex pairs and single stocks have their own volatility, so the column is a yardstick, not a forecast.

Margin loans on stocks

For stocks, the borrowing limit is set by the Federal Reserve's Regulation T. Its margin supplement, 12 CFR 220.12, requires 50% of the current market value for a margin equity security, or the percentage set by the exchange or regulator where the trade occurs if that is higher. That caps a new stock purchase at 2:1.

After the purchase, FINRA Rule 4210 requires equity of at least 25% of the current market value of long margin securities. Separately, new margin purchases require at least $2,000 of equity in the account, although cash beyond the cost of the purchase is not required. Firms may set higher "house" requirements.

Illustrative example: 2:1 on $10,000

A trader with $10,000 buys $20,000 of stock at $50 a share (400 shares), borrowing $10,000. The 8% annual margin rate is an assumption: the SEC notes that margin rates vary substantially between firms, and the bank prime rate was 7.00% in early October 2026 (FRED). One year of interest costs $800.

Stock after one year	Position value	Equity after repaying $10,000 + $800	Return on $10,000 (margin)	Return without margin
+20%	$24,000	$13,200	+32%	+20%
0%	$20,000	$9,200	−8%	0%
−20%	$16,000	$5,200	−48%	−20%

The gain grows from 20% to 32%, but the loss grows from 20% to 48%: interest makes the magnification lopsided. The formula gives the same answers: 2 × 20% − 1 × 8% = 32%, and 2 × (−20%) − 8% = −48%.

The price that triggers a maintenance call

Because the loan stays fixed while the shares move, the price at which equity falls to the maintenance level can be calculated in advance:

P_call = loan ÷ (shares × (1 − m))

m = maintenance requirement (0.25 under FINRA Rule 4210; higher at many firms)

In the example, $10,000 ÷ (400 × 0.75) = $33.33, a 33.3% fall from $50. With a 30% house requirement the trigger is $35.71, a 28.6% fall, and if a year's $800 of interest were added to the loan unpaid, the 25% trigger would rise to $36.00.

Portfolio margin, an alternative under Rule 4210(g) open to customers approved for writing uncovered options, sets requirements from simulated price moves (±15% for individual stocks, +6%/−8% for high-capitalization broad index products), which usually allows more leverage on hedged portfolios. Separately, FINRA replaced the pattern day trader rules, including the $25,000 minimum, with intraday margin standards effective June 4, 2026, as set out in Regulatory Notice 26-10; firms may phase them in until October 20, 2027, so a given broker may still apply the old rules until it switches.

Futures, options and forex

In derivatives, leverage comes from the contract rather than from a loan. The deposit is not a down payment: CME Group's margin course describes futures margin as money kept on hand with the broker, typically 3–12% of the contract's notional value against up to 50% for securities, which implies roughly 8:1 to 33:1 on the deposit alone.

Illustrative example: one E-mini S&P 500 contract

Under CME Rulebook chapter 358, each E-mini S&P 500 contract is valued at $50 times the index. With the index at about 7,800 (it closed at 7,805.45 on October 13, 2026), one contract controls $390,000. Assume an initial margin of $27,000, inside CME's 3–12% range; actual requirements change with volatility and differ by broker.

A 2% index move is 156 points, or $7,800 per contract: 28.9% of the $27,000 deposit.
The deposit-based leverage is $390,000 ÷ $27,000 ≈ 14.4:1, and a 540-point (6.9%) move would consume the whole deposit.
Gains and losses are settled daily (CME's mark-to-market course describes daily marking as a defining feature of futures), so a loss reaches the account the same day, not at the end of the trade.

The margin sets the maximum leverage, not the actual one. A trader holding one contract in a $390,000 account has 1:1 exposure; the same contract in a $30,000 account is 13:1.

Options: leverage built into the price

A bought option controls 100 shares for a premium that is a fraction of their price. The SEC's bulletin on leveraged investing strategies works through a $70 call bought for $2.20 on a $68 stock: when the stock rises to $80 (+17.6%), the call is worth $10.20 (about +364%), roughly 20 times the stock's percentage move. If the stock is at $65 at expiration, the call expires worthless and the whole $220 premium is lost. Because an option's sensitivity to the share price (its delta) shifts with price and time, this effective leverage is not fixed.

Retail forex and crypto perpetuals

For retail forex, 17 CFR 5.9 requires dealers to collect a security deposit of at least 2% of notional value on major currency pairs and 5% on all others, which caps leverage at 50:1 and 20:1. The National Futures Association designates which currencies are major and can set higher deposits; the 2% rate applies only when both currencies in the pair are major. At 2%, a $100,000 position needs a $2,000 deposit, and a 1% move against it costs $1,000, half the deposit. In the US, a crypto perpetual can be listed as a regulated futures contract: on May 29, 2026 the CFTC approved KalshiEX's BTCPERP, a perpetual contract referencing the spot bitcoin price, for listing as a futures contract.

Volatility drag and daily resets

When leverage is held constant, by rebalancing every day as leveraged funds do, volatility becomes a cost that grows with the square of leverage. For a position with expected arithmetic return μ and volatility σ, the approximate long-run growth rate is:

g ≈ L × μ − (L − 1) × c − L² × σ² / 2

g = annualized compound (geometric) growth rate
μ = the asset's expected arithmetic annual return
σ = the asset's annualized volatility (standard deviation of returns)
c = annual financing cost on the borrowed part

Using the S&P 500's annualized volatility of 18.1% over the ten years to October 13, 2026 (computed from FRED daily closes), the drag term L²σ²/2 is about 1.6% a year at 1x, 6.6% at 2x and 14.8% at 3x. Doubling leverage doubles the expected arithmetic return but quadruples the drag, so a 2x position's compound return falls short of twice the index's compound return by about σ², roughly 3.3 percentage points a year at that volatility, before fund expenses and financing.

Illustrative example: a 2x fund over ten choppy days

An index starts at 100 and swings sharply for ten days; a fund delivers exactly twice each day's return. Fees and financing costs are ignored.

Day	Index return	Index level	2x fund return	2x fund value
1	+6%	106.00	+12%	112.00
2	−5%	100.70	−10%	100.80
3	+4%	104.73	+8%	108.86
4	−6%	98.44	−12%	95.80
5	+5%	103.37	+10%	105.38
6	−4%	99.23	−8%	96.95
7	+6%	105.19	+12%	108.58
8	−5%	99.93	−10%	97.73
9	+4%	103.92	+8%	105.54
10	−3%	100.81	−6%	99.21

The index ends up 0.81%, so twice its return would be +1.61%, but the fund ends down 0.79% although it hit its target every day. Path dependence cuts both ways: in a steady trend of +1% a day for ten days, the index gains 10.46% and the 2x fund 21.90%, more than double. The SEC's updated investor bulletin on leveraged and inverse ETFs (August 29, 2023) and FINRA Regulatory Notice 09-31 (June 11, 2009) both describe this reset effect; the FINRA notice cites an oil and gas index that gained 2% over five months while a 2x daily fund fell 6%.

The cap on fund leverage

Funds registered with the SEC are limited by Rule 18f-4, adopted on October 28, 2020. Under the rule text, a fund's value at risk (VaR, an estimate of a loss threshold at a given confidence level) generally may not exceed 200% of the VaR of its reference portfolio, or 20% of net assets under the absolute test; a leveraged fund tracking an index must use that unleveraged index as its reference. The SEC's adoption announcement states that this effectively limits leveraged and inverse funds to 200% of the index's daily return.

What regulators' data shows

In the US, every retail forex dealer must calculate each calendar quarter the percentage of non-discretionary retail accounts that were profitable and not profitable, under 17 CFR 5.18(i). Fees and commissions are deducted and deposits and withdrawals excluded, and an account that breaks even counts as not profitable. 17 CFR 5.5(e) requires the figures for the four most recent quarters in the risk disclosure statement given to customers, with the legend:

"PAST PERFORMANCE IS NOT NECESSARILY INDICATIVE OF FUTURE RESULTS." (17 CFR 5.5(e)(2))

Customers and prospective customers can also request five years of quarterly figures. The numbers differ by dealer and quarter, so the relevant ones are in a given dealer's own disclosure.

The most-cited aggregate figure is European. When the European Securities and Markets Authority (ESMA) restricted contracts for difference (CFDs) for retail clients, its March 27, 2018 announcement reported that 74–89% of retail CFD accounts typically lose money, with average losses per client of €1,600 to €29,000. The same measures capped retail CFD leverage at 30:1 for major currency pairs down to 2:1 for crypto assets. This is EU data on a product US retail customers generally cannot trade, so it shows a pattern rather than a US figure.

Frequently asked questions

Can a leveraged trade lose more than the money put in?

Yes, in several cases. The SEC's leveraged-strategies bulletin shows a margin purchase at $50 with $25 of the trader's money falling to $15, which wipes out the $25 and leaves $10 plus interest still owed to the broker. The bulletin adds that writers of uncovered calls face potentially unlimited losses, while option buyers can lose at most the premium. The mandatory retail forex risk disclosure likewise warns that a customer may lose more than the deposit.

Can a broker demand more than FINRA's 25% maintenance minimum?

Yes. Rule 4210 sets a floor, and firms commonly apply higher house requirements to particular stocks or to whole accounts. Investor.gov's margin call entry notes that a firm may change its margin call threshold at any time, can sell securities to cover a shortfall without informing the customer in advance, and may sell even after saying the customer has a set number of days to meet a call.

Are 3x leveraged ETFs still allowed?

Rule 18f-4 generally limits new funds to 200% of their index's VaR, which works out to a 2x daily multiple. Funds that were operating on October 28, 2020 with a higher stated multiple, such as 3x, may continue if they disclose that they are not subject to the limit and do not increase their multiple or change their underlying index.

How is margin interest charged?

The margin agreement sets out how interest is calculated, and the SEC's margin-interest bulletin says firms generally must give at least 30 days' written notice of changes in the method of computing interest. Some firms net cash in a separate cash account against the loan, reducing the interest charged; others charge on the full loan, so the SEC suggests asking how accrual and netting work.

Why does a short sale require 150% margin?

Regulation T sets the requirement for a short sale of a non-exempted security at 150% of its current market value. The sale proceeds supply 100%, so the trader deposits the other 50%, the same proportion as a purchase. Because a rising stock has no upper price limit, the loss on a short position has no fixed ceiling.

Checks to run before using leverage

Compute the ratio: position value ÷ own equity, using the notional value for futures and forex, not the deposit.
Compute the wipe-out move (1 ÷ L) and the margin-call price, and compare them with the asset's past single-day moves.
Put the financing cost into the return formula and find the break-even return for the intended holding period.
For a leveraged or inverse fund, check the reset period in the prospectus; returns over longer periods will differ from the stated multiple.
Read the margin agreement for house requirements, interest method and liquidation terms; for forex, read the dealer's quarterly profitability disclosure.
Convert the intended risk into a position size; the Position Size & Risk calculator turns an account size, risk percentage and stop distance into a share or contract count.