The pool of negative-yielding euro investment-grade corporate bonds rose grew in July to its largest on record, according to data from Tradeweb released on Monday.

Bond markets rallied sharply in July, sending yields tumbling across the world as a slowdown in economic momentum, fears around the Delta variant and the unwinding of bets against bonds all sent investors into fixed income markets. 

Some 1.87 trillion euros of investment-grade corporate debt traded on the Tradeweb platform closed July with a sub-zero yield, accounting for 50.7% of the nearly 3.7 trillion euro market, according to Tradeweb data going back to 2016.

In June, negative-yielding corporate debt amounted to 1.3 trillion euros, or 37.5% of the total.

The pool of negative-yielding euro-denominated government debt, meanwhile, rose to its highest since January at 6.54 trillion euros, or 70.8% of the total, according to Tradeweb.

The pool of negative-yielding British government bonds increased slightly to 684 billion pounds, still 26% of the total market, unchanged from May and June.

(Reporting by Yoruk Bahceli; editing by Sujata Rao) ((Yoruk.Bahceli@thomsonreuters.com; +44 20 7542 7571; Reuters Messaging: yoruk.bahceli@thomsonreuters.com))