(Bloomberg) -- As Larry Fink predicts bouts of volatility in bond markets in the coming years, his firm is leading a push among mutual fund firms to reinforce their defenses.

Fink’s BlackRock has increased the amount its mutual funds can collectively borrow to meet withdrawals to $2.1 billion as of November from $500 million in early 2013, regulatory filings show. Eaton Vance, Goldman Sachs Group and Guggenheim Partners are among the firms that have also arranged new borrowing agreements or bolstered existing ones in the past year.

Subscribe Now

Access to premium content including in-depth coverage of mutual funds, hedge funds, 401(K)s, 529 plans, and more.

3-Week Free Trial

Insight and analysis into the management, marketing, operations and technology of the asset management industry.