commodities vs commodity futures investing, position, reading, understand, only

grharmeyer

Is reading 48 about investing in commodities or commodity futures? It seems as if the terms are used interchangeably. P118 says that the sources of return for a collateralized futures position are roll yield, collateral yield and spot price return. I understand roll and collateral yield. But how are we making a return on the spot price when we only own the future? A simple example would be appreciated.