Reverse cash and carry is an arbitrage strategy that involves:

1. Selling an asset in the cash market (spot market)

2. Buying the same asset in the futures market (at a lower price)

3. Shorting the asset until the futures contract expires

The goal is to profit from the price difference between the cash and futures markets, while minimizing risk. Here's how it works:

1. Sell the asset in the cash market at a higher price (e.g., $105)

2. Buy the same asset in the futures market at a lower price (e.g., $100)

3. Short the asset (borrow and sell) until the futures contract expires

4. Buy the asset back in the cash market to cover the short position and pocket the profit ($5)

This strategy is called "reverse cash and carry" because you're selling the asset for cash in the spot market and buying it back in the futures market, while shorting the asset until the futures contract expires. It's a low-risk strategy, as you're not exposed to market fluctuations, and the profit is locked in through the futures purchase.

Reverse cash and carry is commonly used in commodities, bonds, and currency markets, where the price difference between cash and futures markets can be significant. However, it requires access to both cash and futures markets, and the ability to short the asset until the futures contract expires.