Dow, S&P 500 cling to gains on lower yields, Apple slides 4%

Apple down 4% on move to drop iPhone production boost; US 10-yr Treasury yields ease from 12-year highs; Biogen soars on landmark Alzheimer's data

The Dow and the S&P 500 indexes gained in volatile trading on Wednesday as easing Treasury yields gently lifted rate-sensitive growth stocks, while losses in Apple Inc after it dropped plans to boost iPhone production weighed on the Nasdaq.
 

Equity markets also got a boost from a Bank of England decision to restore financial stability by buying as many long-dated government bonds as needed. The move lifted British bond prices and pushed global benchmark yields lower.
 

The yield on the U.S. 10-year Treasury bill came off 12-year highs to hit the day's low of 3.809% by 10:02 a.m. ET, while