Twilio has filed paperwork with the U.S. Securities and Exchange Commission to raise an additional $400 million from the public market. The company said that it will not receive any proceeds from this transaction and that the majority of the shares will be Class A common stock and come from existing shareholders.

Goldman Sachs and J.P. Morgan Securities have been retained as the joint book-running managers for the offering — these are the same financial institutions that backed Twilio’s initial public offering. Twilio’s stock closed the day down 0.18 percent at $60.58, but soon after the filing was made public, the stock sunk nearly 6 percent in after-hours trading.

Five months ago, Twilio filed to go public, seeking to raise at least $100 million as a public company. Shares were originally priced at $15, but on opening day, shares shot up 60 percent to $23.99 before closing up 90 percent at $28.53. As is true of most tech companies, Twilio wasn’t profitable, coming in with $166.92 million in revenue and a net loss of $35.5 million.

The plan to raise funds is likely to combat the end of the 180-day lock-in agreement, which should expire in December. With long-term investors and even early employees anxious to gain some liquidity from their shares, this could be a way to make sure the stock doesn’t fluctuate wildly. Twilio’s performance thus far has been pretty good, with shares up 112 percent since the company’s IPO, but it’s possible that shareholders just want to get out while Twilio’s stock is doing well.

In today’s S-1 filing, the company revealed that in the six months ending June 30, 2016, it had 30,780 active customer accounts. During the same time period, it reported $123.8 million in revenue, with a net loss of $17.5 million — most of the expenses were split between research and development and sales and marketing.

Prior to going public, Twilio said that WhatsApp was a risk for shareholders because its business accounted for 15 percent of revenue for the first three months of this year. For the first six months of 2016, that percentage seems to have dropped to 12 percent. There’s another unnamed customer using Twilio’s programmable messaging and voice products that accounts for an equal percentage of revenue. However, Twilio said that even though there’s a “minimum commitment contract with us, its usage historically has significantly exceeded the minimum revenue commitment in its contract, and it could significantly reduce its usage of our products without notice or penalty.” WhatsApp does not have a long-term contract with Twilio.

The company has since released its first quarterly earnings, which beat Wall Street’s expectations, generating $64.5 million in revenue versus $58.22 million expected. Twilio chief executive Jeff Lawson said:

We delivered strong results in our first quarter as a public company, as we saw continued growth across our product lines. Customers around the world use Twilio to build differentiated experiences for their end users by embedding communications into their software applications. The successful completion of our IPO in June will provide additional capital and brand visibility to drive our growth in the future as we look to fuel the future of communications.

Today’s news comes 24 hours after Twilio filed more paperwork announcing that its chief operating officer, Roy Ng, has transitioned to a new role as senior vice president of commercial operations. A company spokesperson told VentureBeat that Ng will maintain his responsibilities running sales, corporate development and partnerships, business operations, and strategy, but that Twilio has begun a search for a new executive with experience operating a public company to scale.

Get more stories like this on TwitterFacebook