Blockchain security startup Blockaid has secured $33 million in a Series A funding round, led by Ribbit Capital and Variant, with participation from Sequoia Capital, Cyberstarts, and Greylock Partners. Blockaid is a partner of the MetaMask cryptocurrency wallet and aims to prevent malicious transactions. The company’s security platform is now out of stealth and counts MetaMask, OpenSea, Rainbow wallet, and Zerion wallet among its inaugural customers.