The phrase "to affect the market" means that something has an influence or impact on the buying and selling of products, prices, or the overall behavior of businesses in an economic system. Full definition
The prices of gold and other precious metals may decline versus the dollar, which would adversely affect the market prices of the securities of gold and precious metals producers. (ocmgoldfund.com)
With news affecting the market in a large way due to speculation, some see it as a wild and crazy place to get involved in. (coinstocks.com)
It adds to the basis of an income property (hence reducing the gain at sale) but it doesn't really affect the market value of the property directly. (biggerpockets.com)