(Bloomberg) -- Pacific Investment Management Co.’s decision to buy up almost a third of the world’s top-paying government bond came a cropper this week as the Argentine peso collapsed.

The debt securities maturing next June have fallen to a record low of 85 cents on the dollar from 104 cents last Friday. The notes pay a floating coupon tied to the benchmark interest rate. And while Argentina set its seven-day LELIQ rate at an all-time high of 75% on Tuesday, the peso’s tumble amid a shocking defeat in the primaries for President Mauricio Macri outweighed all other factors.

Pimco holds about 30% of the total debt outstanding, according to data compiled by Bloomberg. The investment firm had boosted its exposure earlier in the year before Argentina re-opened the bond sale. A spokesman at Pimco declined to comment on the firm’s holdings.

Nominal returns for the notes have been huge in recent quarters, yet the peso’s status as a global laggard curbed gains. The currency has weakened a world-leading 37% this year, and analysts say it has much further to fall. Pimco’s profits or losses would depend significantly on the extent to which it hedged its foreign-exchange exposure.

When Argentina issued the debt two years ago, the nation’s benchmark rate was a more modest 26% amid optimism that Macri would revive an economy that stagnated under his populist predecessor Cristina Kirchner. Now, the rate is almost triple that and Kirchner is expected to return to office as the vice president on front-runner Alberto Fernandez’s ticket.

--With assistance from Pablo Gonzalez and John Gittelsohn.

To contact the reporter on this story: Ben Bartenstein in New York at bbartenstei3@bloomberg.net

To contact the editor responsible for this story: Julia Leite at jleite3@bloomberg.net

©2019 Bloomberg L.P.