What "shorting the ASX" means
Shorting the ASX means positioning to profit when Australian share prices fall — either a single stock you believe is overvalued, or the broader S&P/ASX 200 index. There is no single "short button" on an Australian brokerage account. Instead, investors have four practical routes, each with different mechanics, costs, and risk profiles. This guide covers all four, the step-by-step broker mechanics of a direct short sale, the legal rules that govern short selling in Australia, and the checks worth running before you place the trade.
The four ways to short an ASX stock
1. Direct short selling through a broker
The classic approach: your broker borrows shares on your behalf, you sell them on market, and you buy them back later — profiting if the price has fallen in the meantime. Full-service brokers and margin platforms offer this facility. Interactive Brokers provides the widest range of shortable ASX stocks for retail clients thanks to its global securities lending network, with a real-time availability checker built into its platform. CommSec offers a more limited shortable list through its margin lending facility.
Direct shorting gives you clean, linear exposure with no expiry date. The trade-offs: you need a margin account, you pay a borrow fee for as long as the position is open, you owe any dividends to the share lender, and your loss is theoretically unlimited if the stock rises. Our guide to covered short selling and stock borrowing in Australia covers the broker-by-broker detail.
2. CFDs — contracts for difference
CFD providers such as CMC Markets and IG let you open a short position without borrowing any shares. A CFD is a derivative contract in which you exchange the difference between a stock's entry and exit price with the provider — sell the CFD short and you profit when the underlying falls.
CFDs are the most accessible route for retail traders: there is no locate process, single-stock and index exposure sit in one account, and position sizes can be small. The costs are real, though. Leverage magnifies losses as well as gains (ASIC caps retail CFD leverage on individual shares at 5:1), overnight funding charges accrue every day the position stays open, and you carry counterparty risk against the provider rather than holding an exchange-traded instrument.
3. Exchange-traded options — puts and XJO index options
Buying a put option gives you the right to sell a stock at a fixed strike price before expiry. If the stock falls below the strike, the put gains value; if it does not, you lose only the premium paid. Exchange-traded options are quoted on the larger ASX names, so puts work best for shorting liquid, big-cap stocks.
To short the whole market, XJO options over the S&P/ASX 200 index are the standard instrument. They are European-style (exercisable only at expiry) and cash-settled at A$10 per index point — no shares change hands. Buying XJO puts is a defined-risk way to position for a market fall or to hedge a long portfolio.
The structural cost of options is time decay: every day that passes without the fall you expect erodes the premium, and an option that expires out of the money is worth nothing. You need to be right on direction and timing. For a full comparison, see short selling vs put options.
4. Inverse ETFs — BEAR and BBOZ
Inverse ETFs are the only way to short the ASX from an ordinary, unleveraged share trading account — you simply buy a fund that rises when the market falls. BetaShares BEAR targets roughly the opposite of the ASX 200's daily move (about -0.9x to -1.1x), while BBOZ is the leveraged version, targeting around -2x to -2.75x of each day's move. Your maximum loss is what you paid for the units, no margin account is required, and there are no borrow fees or margin calls.
The critical caveat is daily-rebalance decay. These funds reset their exposure every day, so over multiple days your return compounds path-dependently rather than tracking the index's total move. In a choppy, sideways market a leveraged inverse ETF like BBOZ can lose money even if the index finishes exactly where it started, because each down-then-up round trip erodes the fund's value. Inverse ETFs — especially leveraged ones — are tools for short holding periods and tactical hedges, not long-term bearish positions.
Step by step: how a direct short sale works
- Open a margin account: Short selling requires margin approval with a broker that offers stock borrowing.
- Locate the borrow: Before your order can execute, the broker must confirm shares are available to borrow from its lending pool. If no borrow exists, the order is rejected — Australian law does not allow the sale to proceed uncovered.
- Post margin: You lodge collateral, typically 25-50% of the position value at Interactive Brokers and up to 100% or more for volatile stocks at other brokers. If the stock rises, you will be asked for more.
- Sell on market: The order executes flagged as a short sale, as required by ASIC's transaction reporting rules.
- Pay the borrow fee: Charged daily as an annualised rate on the position's market value — roughly 0.25-1% p.a. for blue chips like BHP or CBA, 1-5% for mid-caps, and anywhere from 5% to 50%+ for hard-to-borrow, heavily shorted names. Any dividends paid while you are short are owed to the lender.
- Buy to cover: You close the position by buying the same number of shares and returning them. The difference between your sale and buyback prices, minus fees, is your profit or loss.
Cost and risk comparison
| Method | Maximum loss | Ongoing costs | Best suited to |
|---|---|---|---|
| Direct short sale | Unlimited — no ceiling on how far a stock can rise | Borrow fee (0.25-50%+ p.a.), dividends owed, margin interest | Longer-horizon, high-conviction positions in borrowable stocks |
| CFDs | Can exceed your deposit at 5:1 leverage before stop-outs | Overnight funding charges, spread, leverage risk | Short-term trades and index positions with small capital |
| Put options / XJO puts | Capped at the premium paid | Time decay — premium erodes daily toward expiry | Defined-risk bearish trades and portfolio hedges with a timeframe |
| Inverse ETFs (BEAR, BBOZ) | Capped at the amount invested | Management fees plus daily-rebalance decay in volatile markets | Tactical, short-duration market hedges from a standard account |
The pattern to note: the routes with capped losses (options, inverse ETFs) charge for that protection through decay, while the routes with linear payoff (direct shorts, CFDs) expose you to unlimited or leveraged losses. There is no free structure — you are choosing which cost you prefer to carry.
The legal layer: what Australian law requires
- Covered short selling only: Section 1020B of the Corporations Act 2001 prohibits naked short selling. A borrow arrangement must be in place before the sale — your broker enforces this at the locate step, and breaches attract civil and criminal penalties.
- Net short position reporting: Positions above the ASIC reporting threshold — A$100,000 in value or 0.01% of the company's issued capital, whichever is less — must be reported to ASIC by 9:00 AM the next trading day. Reporting sits with the position holder (institutions and larger traders); retail-sized positions rarely reach the threshold.
- T+4 publication: ASIC aggregates the reported positions per stock and publishes the totals four trading days later. This is the dataset behind every short interest figure on Shorted.com.au — always four trading days behind the market.
- CFD product intervention: ASIC caps retail CFD leverage (5:1 on shares, 20:1 on major indices) and mandates negative balance protection on retail CFD accounts.
Pre-trade checklist: before you short anything
- Check the current short interest. Look up the stock on Shorted.com.au — for example BHP's short position page — to see what percentage of issued capital is already sold short and how that has trended. A stock at 12% short is a very different proposition from one at 1%.
- Check days to cover. The screener lets you filter by short interest and days to cover — how many days of average volume shorts would need to exit. High days to cover means a crowded exit if the trade turns.
- Gauge the crowding. Scan the top 100 most shorted ASX stocks. If your target is already near the top of the list, the bear case is well known, borrow will be expensive, and squeeze risk is elevated.
- Assess squeeze risk. Heavily shorted stocks with small free floats and upcoming catalysts (earnings, drill results, takeover interest) can rally violently as shorts rush to cover. If the shares are hard to borrow, a recall can force you out at the worst possible moment.
- Size the position and define the exit. Because short-side losses grow as the trade moves against you, position sizing matters more than on the long side. Decide before entry what price or event invalidates the thesis, and cap the position at a level where being wrong is survivable.
Key takeaways
- There are four ways to short the ASX: direct share borrowing, CFDs, exchange-traded put options (including XJO index puts), and inverse ETFs like BEAR and BBOZ
- Capped-loss structures pay for the cap through decay; linear structures carry unlimited or leveraged downside
- Leveraged inverse ETFs rebalance daily and bleed value in choppy markets — they are short-duration instruments
- Only covered short selling is legal in Australia; ASIC publishes reported net short positions daily with a T+4 delay
- Always check current short interest, days to cover, and squeeze risk on Shorted.com.au before opening a position