Surging share prices has propelled three little-known ASX-listed tech companies on to the all-cap technology index later this month, a move that will see more investors pile in.

Utilities software developer Gentrack, cybersafety platform Qoria and wealth management software provider Bravura Solutions are due to join the S&P/ASX All Technology Index on June 24. Their inclusion will trigger buying from passive funds that track the index as well as active investors who use it as their benchmark.