Twitter co-founders Evan Williams and Jack Dorsey suffered a combined $750m loss in net worth, after the company's shares plunged following its disappointing quarterly results.
In its earnings release that went online before schedule, the company posted weaker-than-expected results for the first quarter. Revenue in the first quarter rose 74% to $436m (£286m, €399m), up from $250m a year earlier, but missing analysts' forecast of $456.2m.
In addition, the company cut its full-year revenue outlook to a range between $2.17bn and $2.27bn, down from the previous range of $2.3bn to $2.35bn. The company also cut its revenue forecast for the second quarter.
Following the results, Twitter shares closed down more than 18% at $42.27 on 28 April. In after hours, the shares fell a further 1%, causing a sizable loss to its biggest shareholders.
Co-founder Williams, who holds a 7.5% stake in the company, lost about $525m, according to the Bloomberg Billionaires Index. Meanwhile, Dorsey lost about $220m.
"No one likes to see a stock fall like that," Williams said in an interview with Bloomberg TV.
"But, honestly, I have the utmost faith in the long-term business of Twitter and it's easy to get caught up in the ups and downs of the stock market."