I think a credit instrument is a written evidence of the extension of a loan.

我认为信用工具就是发放贷款的书面证明。

youdao

A new financial instrument-the loan securitization, can transfer funds into the hands of the loan through this channel.

一种新的金融工具—贷款证券化，使资金拥有者可以通过这一渠道将资金转移到贷款者手中。

youdao

The borrowers could be hedge funds, who either are trying to short a stock or scrambling to cover a stock loan that has been called in, or they could be investment houses that need an underlying instrument for a derivatives contract.

FORBES: Shortchanged