I would like to calculate historical Value at Risk for a portfolio that includes both long and short positions in forward contracts.
The part that confuses me is that I wonder whether the VaR of the different positions should better netted or summed up.
For example, I purchased a December contract and sold another contract for same delivery month. If VaR on the long position is 1000 usd and sales is also 1000 usd, can I net them?