Shares of urban-gro Inc. plummeted 74.3% in premarket trading, on the same day that they are slated to move over to the Nasdaq from the OTCQX Marketplace, after a large stock offering priced at a deep discount. Colorado-based Urban-gro, which makes commercial controlled environment agriculture facilities, said late Thursday that its public offering of 5.4 million shares price at $10 a share, but the stock had closed Thursday at $47.00. The stock had pulled back 37.3% over the past four sessions, following a 476.9% rocket ride higher on Feb. 5. In a filing on Wednesday, the company noted that the stock had “recently experienced extreme price volatility,” but said that it had not experienced any material change in its financial condition or business that would explain the volatility. In that filing, the company said it had a firm commitment for a public offering of 3.46 million shares at an “assumed” offering price of $13.00 a share, which would have provided proceeds of about $45 million. At that time, the company said it expected to have about 8.2 million shares outstanding after the offering. The stock has rocketed 683.3% over the past three months through Thursday, while the S&P 500 has gained 10.7%.