What happened Shares of Forterra (NASDAQ: FRTA) plunged as much as 14.4% in trading Thursday after announcing the pricing of a stock sale. The stock didn't recover much from lows and was still down 11.8% for the day at 3:40 p.m. EDT. So what The company announced the sale of 10 million shares of Forterra stock at a price of $13.50 per share, below yesterday's closing price of $14.61 per share. This is notable because the offering didn't go to Forterra itself, but was rather a sale by the company's largest shareholder, Lone Star Funds. That sale is what's driving the initial slump in the stock, but clearly shares fell below that, hitting as low as $12.50 per share today. Image source: Getty Images. When a big stockholder sells a big portion of stock, investors should take notice. Maybe their investment thesis changed or they need to raise cash, but if they're abandoning a stock then investors should reconsider if their thesis has changed as well. Now what This sale doesn't fundamentally change Forterra's operations at all, so investors shouldn't panic sell. But the idea that a large shareholder is selling its stock is notable. It's important to note, however, that the sale happened at nearly four times the price of the stock's 52-week low, so this may just be opportunistic selling for Lone Star Funds. 10 stocks we like better than Forterra, Inc. Common StockWhen investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* David and Tom just revealed what they believe are the ten best stocks for investors to buy right now... and Forterra, Inc. Common Stock wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of August 1, 2020 Travis Hoium has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.Source