1.   But analysts said the overall gain in January masked underlying strength.

2.   But the gains masked unusual market turmoil.

3.   But those gains mask a growing disparity in the overall market.

4.   But those similar gains mask some underlying turmoil, money managers say.

5.   That pushed down bond prices on Wednesday, but analysts contended that the gain masked an economy that was actually decelerating.

6.   The gains mask weakness, analysts said.

7.   The sharp drop at Ebay suggests that its dazzling stock gain may be masking a major weakness.