Innovative Industrial Properties Inc., an investment company that aims to buy buildings and lease them to growers of medical marijuana, announced Oct. 12 that it is looking raise $15 million by selling 600,000 shares of preferred stock in the company at $25 per share.

The company also said it is offering the underwriters the option to buy up to an additional 90,000 preferred shares. If the company ever elects to pay dividends, holders of preferred stock would get paid ahead of holders of common stock.

The offering is slated to close Oct. 19.

Innovative Industrial Properties (NYSE: IIPR), one of the few companies focused on cannabis to be listed on a major stock exchange, went public in late 2016.

When it debuted on the exchange, shares were priced at $19.15.

The company’s stock has fluctuated since it began trading, bottoming out a few days after the company went public at $15.40, then peaking a month later at $19.71.

The stock was $19.10 per share as of market close Oct. 12.