** Asset manager Affiliated Managers Group's AMG.N shares rise 4.2% to $354.71

** Stock slipped 7% on Tuesday after Bloomberg News reported that U.S. Treasury officials had raised concerns about several Wall Street tax strategies, ​saying it may be "too good to be ‌true"

** The products under scrutiny ​include so-called 351 conversions, box-spread exchange-traded funds, products that offset ordinary income, and funds that avoid dividend income by flipping between other ETFs, the report said

** AMG owns a stake in quant hedge fund AQR Capital Management, which offers so-called tax-aware strategies such as AQR TA Delphi Plus Fund

** "We believe the weakness in AMG in particular is overdone - as the move seemingly suggests 100% of the firm's tax-aware platform would be at risk," TD Cowen analyst Bill Katz said

** "We suspect the bulk of AMG's exposure centers on regular way tax loss harvesting strategies, seemingly beyond the purview of the scrutiny"

** Up to last close, AMG stock up 18.1% YTD