Where does FB say it sells your data? Was there a news article about it? I see this repeated about other tech companies as well but I can never find where they

Where does FB say it sells your data? Was there a news article about it? I see this repeated about other tech companies as well but I can never find where they say they sell my data. It seems weird companies would sell their most valuable asset, rendering themselves moot. My understanding is these companies allow advertisers to target users, but never sell the data.