The Thomson Reuters’ Post-Venture Capital Index (PVCI) gained 15 points points to end September at 1151.52, a 1.33 percent rise from the 1136.39 total at the end of August.
The index value ending on Sept. 29 stands more than 185 points, or 19 percent, over the 966 point value that started the year.
The Nasdaq and the S&P also gained value in September.
At the end of the month, the PVCI was comprised of 339 companies. Of the stocks tracked, 233 advanced in value in September while 106 declined.
The number of companies in the index rises and falls, depending on new issues or as the companies fold or are acquired. Also, companies remain in the index for only 10 years.
A total of 54 of the advancing stocks in September were in computer software and services, while biotech saw 43 stocks rise. The largest group of decliners was also in biotech with 32, followed by computer software with 23 decliners.
Facebook, as it typically does each month, ranked as the company with top market value, as of Sept. 29, followed by Tesla and Kinder Morgan.
The index is calculated daily and does not take into account dividends.
It began in January 1986 with an initialized index value of 100.
Download Data: PVCI as of Sept. 29, 2017
Photo of of a businesswoman drawing a growth chart courtesy of Manuel-F-O/iStock/Getty Images