Why did Antonio signed the bond with Sherlock?

Antonio signed the bond with Sherlock to secure a loan that he desperately needed for his business ventures. He was motivated by his desire to help his friend Bassanio woo Portia, as Bassanio required funds to compete for her hand. The bond's terms, which stipulated a pound of flesh as collateral, reflected Antonio's confidence in his own financial success, believing he could repay the loan in time. However, this decision ultimately set the stage for the dramatic conflict in "The Merchant of Venice."