According to your question, if you sign a copper contract of100t, and you are afraid of risks after 50 days, it means that you have demand for the spot, are afraid of risks and want to use the futures market to avoid risks. For example, if you sign a contract in August, you can buy a futures contract in the opposite direction from August in the futures market.
Because the price changes in the futures market and the spot market tend to be consistent, and as the futures contract approaches delivery, the futures price and the spot price tend to be consistent.
Therefore, after 50 days, regardless of whether the August contract is profit or loss, because you made the opposite transaction in futures, you can close the futures contract after 50 days and hedge the spot trading with the loss or profit in futures trading, so that your spot trading risk can be avoided through futures trading.