This weeks version of the Weekend Research report will focus on the hot IPO stocks where insiders can't wait to dump shares. Both Acacia Communications (ACIA) and Twilio (TWLO) came out with secondary offerings last week after the stocks were two of the most successful IPOs of the last few years, if not ever. Investors might want to use the rest of the weekend to research the logic of holding these stocks. Acacia completed an offering of 4.5 million shares at $100 with insiders selling 3.3 million shares plus an option for another 675,000 shares. The optical networking stock hit a high of nearly $130 suggesting insiders are leaving a lot of money on the table pricing this low. Twilio filed a proposed offering of $400 million with the company only selling $50 million worth of shares. The cloud communications platform has a market value of roughly $6 billion with revenue expectations of only $255 million for the year. No wonder insiders want special approval to dump around 6 million shares with the stock trading at $60. The better idea is to buy previous hot IPOs that are now beaten down. Both Twitter (TWTR) and Zoe's Kitchen (ZOES) trade around $20 after trading at prices of $40 and even higher. Twitter likely has a bid on the table around $24 providing support on the downside and a successful live-streaming business to provide a catalyst for higher prices. Zoe's Kitchen faces a tough promotional environment in the fast-casual restaurant space, but the stock is down 50% after a slight guide down on full-year guidance. Both stocks will bounce on inline Q3 results. Instead of chasing the hot IPOs where insiders are dumping shares, look for some previous hot stocks that are now beaten down. Disclosure: Long TWTR and ZOES