Following a shocking spike in volatility in a key source of short-term funding for asset managers, banks and pension funds, market participants say there is no silver bullet to prevent a repeat.

The “unprecedented” volatility in December 2016 in the European market for repurchase agreements, or repos, was attributed to a confluence of factors, including a shortage of high-quality collateral as well as post-financial crisis regulation that the market has yet to fully adjust to.