Blockchain stocks are regular stock market shares of companies involved with blockchains. Although there are ETFs on the market that track the price of the Bitcoin (BTC) and Ethereum (ETH) cryptos directly, blockchain companies are not crypto companies themselves. Rather, they offer products that use blockchains in some manner.
For example, NVIDIA's GPUs are widely used in crypto mining. Square's Cash App lets people buy and sell Bitcoin. IBM is using blockchains to help customers build supply chains (see
IBM Blockchain), and Amazon's AWS cloud computing lets customers manage their own blockchain platforms (see
Amazon Managed Blockchain).