"白投" (White drop) in Engpsh refers to "Airdrop".

An airdrop is a marketing strategy used in the cryptocurrency and blockchain industry where tokens or coins are distributed for free to a large number of wallet addresses. This is often used as a way to increase the visibipty and adoption of a new cryptocurrency or blockchain project.

For example:

"The company will be holding an airdrop for its new token next month."
(公司将在下个月举行新币的白投。)

"Many people have received free tokens from the airdrop campaign."
(很多人已经从白投活动中获得了免费的代币。)