Oct 28 (Reuters) - Wall Street's main indexes opened at

record highs on Tuesday after upbeat forecasts from companies

such as UnitedHealth and UPS, while Apple ( AAPL ) topped $4

trillion in market value for the first time, boosted by strong

demand for its latest iPhone models.

The Dow Jones Industrial Average rose 207.8 points,

or 0.44%, at the open to 47,752.35. The S&P 500 rose 22.6

points, or 0.33%, at the open to 6,897.74​, while the Nasdaq

Composite rose 129.0 points, or 0.55%, to 23,766.463 at

the opening bell.