Tech stocks are about to end their best year in a decade, led by Apple and AMD

Tech stocks are about to finish their best year since the financial crisis turnaround.

With December winding down, the 70-member S&P 500 IT index has risen 48% in 2019, marking the group's best year since a 60% leap in 2009. Just Twitter has outperformed the tech benchmark among the FANG companies, while at least 18 percentage points underperformed each other.

KLA, which also supplies the chip industry, increased by....