Shares of one of the year's hottest tech IPOs are crashing after it said it wanted to sell more stock

Twilio's stock is down roughly 10% in midday trading on Monday, after the tech company announced plans to sell more equity in a follow-on stock offering.

Twilio, which provides phone and text message services to app developers, went public in June in a blockbuster debut that saw its shares surge 90% on its first day of trading. The IPO was a standout in an incredibly slow market his year (although enterprise tech company Coupa saw its shares more than double in its Wall Street debut last week.)

But Twilio's honeymoon on Wall Street appears to be over. The company's spectacular rally, which carried its stock from a $15 IPO price all the way to a 52-week high of $70.96 earlier this year, came to a sudden halt after its revelation on Friday that it was planning a follow-on stock offering.

The company did not say how many shares it intended to sell. But investors clearly were not happy with the news. Shares of Twilio plunged 10% to $54.49 on Monday.

Here's a chart of Twilio's stock since its June IPO: