Through Tuesday's close, the Dow Jones industrial average gained 0.87% on a total return basis year-to-date, while the average constituent return over the period was -0.74%. The average daily volatility of index constituents so far in 2018 is 1.53%. Comparatively, the average constituent return and volatility in 2017 was 21.37% and 0.96%, respectively.
The index is market-cap weighted, with larger companies having greater influence over the total index return. Apple and Microsoft, the two largest companies in the index, returned 10.59% and 18.97%, respectively, year-to-date.
It was announced Tuesday that General Electric, which had been in the index since 1907, would be removed. Since the start of 2017, GE has lost about $168 billion in market cap after dropping 45% in 2017 and another 26% year-to-date 2018. Over the 18-month period, the company saw its weight in the index fall to 1.6% from 5%. GE will be replaced by Walgreens Boots Alliance, which will constitute about 1% of the total index market capitalization.