A. If you want to bet the stock market's fall, other than the bear-market funds or puts, the CBOE Volatility Index or VIX (also known as the market's fear gauges) is another effective tool, since volatility spikes when stocks plunge, and in market rallies, volatility recedes. You can purchase the Proshares Ultra VIX Short-term Futures ETF (UVXY) to accomplish the goal.
Complications
However, an investor on VIX ETFs will be better off to understand some of the details before actually putting money into the funds:
1. Aren't directly tied to VIX
The VIX ETFs are not directly tied to VIX because VIX is a mathematical calculation that isn't directly investable. Instead, VIX ETFs are linked to the futures market, and unlike a continuous index, futures contracts expire regularly. As a consequence, don't expect your VIX ETFs' returns mimic exactly the VIX's changes.
2. Not the best for long term investors
All futures-related ETFs face structural limitations because they use derivatives therefore must swap pricier longer-dated contracts for cheaper short-dated ones each month. This "roll" effectively means those funds continually buy high and sell low.
The Bottom Line
The VIX ETFs are best for investors who change their holdings frequently and don't want to use the bear market funds or put options to bet against the markets.