Carvana (CVNA) had the highest return between 2018 and 2019 by a large-cap US stock, returning 380.4%.

ASSET	YEARS	% RETURN
Carvana (CVNA)	2018-2019	380.43%
Okta (OKTA)	2018-2019	351.55%
Advanced Micro Devices (AMD)	2018-2019	340.12%
MongoDB (MDB)	2018-2019	339.73%
Twilio (TWLO)	2018-2019	307.29%
DexCom (DXCM)	2018-2019	279.63%
Natera (NTRA)	2018-2019	271.04%
Ascendis Pharma A-S (ASND)	2018-2019	246.07%
Lattice Semiconductor (LSCC)	2018-2019	231.14%
Paycom Software (PAYC)	2018-2019	229.02%
Sea (SE)	2018-2019	202.41%
Lululemon Athletica (LULU)	2018-2019	199.66%
Chipotle Mexican Grill (CMG)	2018-2019	187.77%
Guardant Health (GH)	2018-2019	181.59%
Axon Enterprise (AXON)	2018-2019	176.32%
Ubiquiti Networks (UI)	2018-2019	169.6%
Frontline (FRO)	2018-2019	163.68%
Atlassian (TEAM)	2018-2019	161.95%
Repligen (RGEN)	2018-2019	154.4%
Roku (ROKU)	2018-2019	154.37%
Veeva Systems Inc Class A (VEEV)	2018-2019	154.27%
argenx NV ADR (ARGX)	2018-2019	152.87%
Tenet Healthcare (THC)	2018-2019	149.38%
Zebra Technologies (ZBRA)	2018-2019	145.38%
Amun Bitwise Select 10 Large Cap Crypto ETP (KEYS)	2018-2019	144.94%

Large-cap stocks are treated as having a market cap of $10B+.