The Tell: Tesla drives up S&P 500’s disruptive tech exposure as the index rides to record highs in October

Tesla is driving up the S&P 500 index’s exposure to disruptive technology, with Big Tech helping to lift the U.S. stock-market benchmark to new peaks this month.

The S&P 500’s technology sector plus Google parent Alphabet, Facebook, Amazon.com and Tesla add up to 40% of the market-capitalization-weighted index, according to a DataTrek Research note Wednesday. “No other broad market index around the world has a 24 percent weight to its top 6 names,” which also include Apple AAPL and Microsoft MSFT, the note shows. 

“We’ve…