ProShares UltraShort S&P500 or S&P 500 Puts: Which Fits?

Two orders can carry the same opinion about the S&P 500. One buys $5,000 of SDS in an ordinary brokerage account. The other buys a single put contract on an index ETF that tracks the S&P 500, with a hypothetical ETF trading at $400, a $390 strike, 30 days left and a premium of $5.00 a share, so $500 for the contract.

Both make money if the index falls. The cost, the worst case and the paperwork all differ.

What is inside each position?

SDS is ProShares UltraShort S&P500. ProShares states its objective as daily results, before fees and expenses, equal to two times the inverse (-2x) of the S&P 500’s daily performance, and lists the fund’s inception date as July 11, 2006 (fund page, as of October 2026). The fund holds no stocks. Its holdings list shows short exposure to the S&P 500 through index swap agreements with a group of large banks and a short position in S&P 500 E-mini futures, with the cash parked in Treasury bills and a money market fund. Each evening it resets that exposure so the next session starts at -2x again.

A put is a contract. It lets you sell the ETF at the strike price. That right lasts until expiration. Cboe’s specifications for options on exchange-traded products set the unit at generally 100 shares per contract, make them American style, so a holder can exercise on any business day until and on the expiration date, and settle an exercise by delivering ETF shares. Expiration falls on the third Friday of the month for standard contracts.

So the $500 put covers 100 shares, or $40,000 of ETF at $400. The $5,000 of SDS carries about $10,000 of short index exposure on the day you buy it.

Where does each one cost you money?

With SDS, the cost comes from the path the index takes. Because the fund resets daily, a month in which the index swings up and down and finishes flat leaves the fund lower, and the loss grows with the size of the swings and the length of the hold. ProShares’ own fact sheet says smaller index moves and higher volatility push results below the daily target over time. The fund also deducts an expense ratio, published on its fund page.

With the put, the cost is time. Its premium is part intrinsic value, what it would be worth if exercised now, and part time value, which shrinks as expiration approaches. At $400 the $390 put has no intrinsic value, so all $500 is time value. If the ETF sits still, that $500 melts toward zero by the third Friday. A drop in implied volatility can cut the price too, even on a day the index slips.

What is the most you can lose?

With the put, the answer is fixed at entry: $500, the premium, plus commissions. It does not matter how far the index rallies.

SDS has no fixed ceiling short of the full $5,000. Each up day for the index takes twice its percentage off the fund, and those losses compound, so a sharp month-long rally can take a large slice of the stake before you react, and only a sell order ends it, whether you place it by hand or leave a stop working with your broker.

Which account approval do you need?

For SDS, usually none beyond a normal account. You are simply buying shares of a fund. Some brokers ask you to acknowledge the risks of leveraged and inverse funds first, and others restrict them.

Options need more. FINRA Rule 2360 bars a firm from taking an options order until it has given you the options disclosure document and approved the account for options trading. Brokers grant it in levels. Buying puts usually sits near the bottom. Under Cboe’s margin terms, long options are paid in full. For what a small account needs before it starts buying contracts, see how much money you need to trade options.

The same month along different paths

Hold both positions for the 30 days to expiration and run the index along each path below. Every figure is hypothetical and ignores fees and commissions.

Close enough to call it even. The put needed the ETF below $385, its strike minus the premium, just to break even at expiration; it got there with room to spare.

Here SDS wins easily. The chop cost it about 1.2%. The put lost everything, because the clock ran out.

Nearly level again. Stretch the rally to ten such sessions and the gap opens: SDS falls to $5,000 x 0.98^10 = $4,085.36, a loss of $914.64, while the put’s loss stays at $500.

Which holding period suits each?

Use SDS when the view is short and you can watch it. A few sessions around a data release or an earnings-heavy week fit well. Past a week or two, check the position against the index, because the reset keeps compounding whether you look or not; the leveraged ETF decay calculator shows what a given path does to a -2x fund.

Use a put when the view has a date attached and you want the loss settled in advance. Pick an expiration that leaves time after the date you expect the move, since time value drains fastest in the final weeks.

ProShares also runs SH, the -1x fund on the same index, which drifts less and moves less, and SPXU, the -3x fund, which drifts more and can lose about three times the index’s daily gain in a single session. The inverse ETF list sets them beside the Nasdaq-100, Dow and Russell 2000 funds.