throwaway account for obvious reasons; here's the background, though:- startup founded in early 2010's, and recently closed Series X fundraising. The company is now profitable and has a decent war chest - employees hold options/common stock and they're now worth $$$$ - with the recent MEGA fundraising, employees have the opportunity to purchase preferred stock, same price as the most recent fundraising - if IPO'd, there's a 9 month cliff from selling.Is this a common practice? What are the benefits of purchasing preferred stocks, given I have commons? What else to look for? And what would you do as an employee in this instance?