No IPO's last week as the summer comes to an end.

A silent week last week as there were no companies that went public. This is normal, seasonal activity but there are five new filings which has analysts pumped about the possibilities of an active September, particularly in the tech sector.

The VIX Volatility Index remains calm and is comfortably below 15. So far for 2016, the average IPO has returned 28% and most of the of IPO's are currently trading above their issue price. For the larger companies that have raised $100 million or more, the average return is an impressive 45%.

First up we have Trade Desk (NASDAQ: TTD). This is an ad agency that offers a real time bidding platform for online ads. The company hopes to raise as much as $86 million. According to their filings, the company was founded in 2009 and has $149 million in sales for the 12 month period ending June 2016.

Apptio (NASDAQ: APTI), which provides on-demand IT management solutions, filed on Friday with the SEC to raise up to $75 million in an initial public offering. The Washington based company was founded in 2007 and shows $143 million in sales for the 12 months ended June 30, 2016. There are no pricing terms set yet.

Chinese company, Gridsum (NASDAQ: GSUM) is looking to raise up to $75 million in an initial public offering. The company is a provider of web, video and mobile big data analytics. They have been around since 2005 and have $45 million in sales for the 12 months ended June 2016. No pricing was available as of this writing.

e.l.f. Beauty (NYSE: ELF) is a beauty company that sells branded cosmetics for the eyes, lips and face at a low price point. The company filed on Friday with the SEC to raise up to $100 million in an initial public offering. They have been in business since 2004 and have $213 million in sales booked for the year.

Lastly we have a biotech. Novan (NASDAQ: NOVN) is a late-stage biotech which according to their filings is developing nitric oxide based therapies for dermatologic indications. The company hopes to raise up to $60 million in an initial public offering. No pricing is available at this time.