BUSINESS DIGEST: FRIDAY, FEBRUARY 6, 1987
LEAD: Markets The Dow Jones industrial average closed above 2,200 in a surge of trading that also lifted broader-based market indicators to new highs. In a day marked by sharp price swings, the Dow added 10.26 points to close at 2,201.49. Volume was 256.7 million shares, the second-busiest session on record.

