Vanguard's website, vanguard.com, intermittently gave users a "this webpage is not available" error after login information is entered into the site.
Users were quick to sound off about it on Twitter.
can't logon to vanguard THE WORLD IS ENDING— biracial af (@alyssakeiko) August 24, 2015
Observation: @Vanguard_Group site appears to be struggling mightily.— Ben Casselman (@bencasselman) August 24, 2015
Vanguard hosts investment portfolios for customers, which includes mutual funds, 401(k) and IRAs.
Linda Wolohan, a spokeswoman for Vanguard, said there was a surge of traffic Monday morning.
"We experienced a brief period of sporadic website inaccessibility at the start of the trading day. We've added capacity to manage the volume," Wolohan said. "During this brief period, clients had the option to call to conduct transactions or check balances. Or they're calling merely for reassurance."
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