This post originally appeared on Business Insider.
After a month of slumping share prices for both Twitter and Square, the CEO of both companies, Jack Dorsey, is no longer a billionaire, according to Forbes.
In the past month, Twitter has fallen from $23.14 per share on Dec. 31st to $15.64 today.
Square, which went public in November, has seen shares fall from $13.09 to $8.40 in the same time frame.
Wednesday’s share prices mark a new all-time low for both companies.
Dorsey was Twitter’s original CEO before leaving in 2008, only to return to the company in 2011 as an executive chairman and eventually returning to the role of CEO this past July. Between his tenures at Twitter, Dorsey co-founded the mobile payments startup Square in 2009 with Jim McKelvy.
You can see the stock performances for both Twitter and Square in the charts below.
Yahoo Finance
Yahoo Finance
See also: The Full Story of Twitter CEO Jack Dorsey is More Awesome than You Realize
