Liquidia Technologies (LQDA) had the highest return on December 26, 2019 by a mid-cap US stock, returning 25%.

ASSET	DATE	% RETURN
Liquidia Technologies (LQDA)	12/26/2019	25%
American Bitcoin (ABTC)	12/26/2019	9.88%
Kinetik (KNTK)	12/26/2019	7.81%
Mirum Pharmaceuticals (MIRM)	12/26/2019	7.47%
Universal Display (OLED)	12/26/2019	6.37%
Bel Fuse A (BELFA)	12/26/2019	5.45%
Arcus Biosciences (RCUS)	12/26/2019	5.27%
NexGen Energy (NXE)	12/26/2019	4.92%
Centerra Gold (CGAU)	12/26/2019	4.65%
Central Puerto (CEPU)	12/26/2019	4.57%
Applied Opt (AAOI)	12/26/2019	4.5%
BBVA Banco Frances SA ADR (BBAR)	12/26/2019	4.27%
Immunovant (IMVT)	12/26/2019	4.13%
B2Gold (BTG)	12/26/2019	4.12%
Northern Oil & Gas (NOG)	12/26/2019	3.91%
Arrowhead Pharmaceuticals (ARWR)	12/26/2019	3.78%
Globalstar, Inc Common Stock (GSAT)	12/26/2019	3.64%
Antero Midstream Partners (AM)	12/26/2019	3.61%
Urban Outfitters (URBN)	12/26/2019	3.38%
Taseko Mines (TGB)	12/26/2019	3.36%
Osisko Gold Ro (OR)	12/26/2019	3.32%
HUTCHMED DRC (HCM)	12/26/2019	3.25%
Merit Medical Systems (MMSI)	12/26/2019	3.25%
Axsome Therapeutics (AXSM)	12/26/2019	3.15%
Ideaya Biosciences (IDYA)	12/26/2019	3.09%

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