Travere Therapeutics (TVTX) had the highest return in August 2008 by a mid-cap US stock, returning 233.3%.

ASSET	MONTH	% RETURN
Travere Therapeutics (TVTX)	August 2008	233.33%
Radian (RDN)	August 2008	108.29%
ATS (ATS)	August 2008	63.17%
American Airlines (AAL)	August 2008	60.19%
Brookdale Senior Living (BKD)	August 2008	44.4%
Nelnet (NNI)	August 2008	43.56%
Ensign (ENSG)	August 2008	38.09%
Assured Guaranty (AGO)	August 2008	37.65%
PDF Solutions (PDFS)	August 2008	37.45%
Liberty Global PLC Class B (LBTYB)	August 2008	31.21%
Insight Enterprises (NSIT)	August 2008	29.9%
Astronics (ATRO)	August 2008	29.55%
Meritage (MTH)	August 2008	29.46%
MGIC Investment (MTG)	August 2008	28.8%
Scotts Miracle-Gro (SMG)	August 2008	26.82%
Graphic Packaging (GPK)	August 2008	26.67%
Central Garden & Pet Company A (CENTA)	August 2008	26.49%
Catalyst Pharmaceuticals (CPRX)	August 2008	25.73%
Bath & Body Works (BBWI)	August 2008	25.7%
Toro (TTC)	August 2008	25.56%
Dillard's (DDS)	August 2008	25.19%
Avis Budget (CAR)	August 2008	24.51%
Central Garden & Pet (CENT)	August 2008	23.84%
Asbury Automotive (ABG)	August 2008	23.37%
ADEIA (ADEA)	August 2008	22.99%

Mid-cap stocks are treated as having a market cap between $2B and $10B.