Based on the deltas, it could be implied that movement restrictions had propelled Amazon and Netflix to a massive year-on-year delta by the end of 2020. Added to this were the concerns over the pandemic that drove pharmaceutical and diagnostic companies to high deltas as well. Meanwhile, companies associated with travel and energy companies had significant drops. By the end of 2021, it could be implied that Alphabet’s steady growth was the fuel that drove the index while pharmaceutical companies began to drag. In the months since November 2021, however, construction, energy and food companies had massive rises while “tech” giants such as Amazon, Alphabet and Tesla were collapsing.

But why is the S&P 500 collapsing? This is attributable to the weighing schema: “Tech” companies have very high weights and an outsized effect on the index. Thus, even when the stock price upticks in these types of companies were minimal, the index would go up. By the same token, when these stocks slip, it gives the appearance of a massive fall. For instance, in the November 2019-20 window, Amazon, Alphabet, Microsoft and Apple is estimated to have contributed about 60% of the uptick in the index while in the three-month window between November 2021 till February, these same stocks have contributed to 59% of the downturn seen in the index.