AngloGold Ashanti (AU) had the highest return in December 2018 by a large-cap US stock, returning 23%.

ASSET	MONTH	% RETURN
AngloGold Ashanti (AU)	December 2018	23.04%
Wheaton Precious Metals (WPM)	December 2018	22.06%
Gold Fields Ltd ADR (GFI)	December 2018	17.72%
Kinross Gold (KGC)	December 2018	16.12%
Agnico Eagle Mines (AEM)	December 2018	12.91%
Companhia de Saneamento Basico do Estado de Sao Paulo SABESP ADR (SBS)	December 2018	8.18%
Genmab A-S (GMAB)	December 2018	6.77%
Palo Alto Networks (PANW)	December 2018	6.6%
Newmont Goldcorp (NEM)	December 2018	6.09%
Barrick Gold (GOLD)	December 2018	5.1%
Broadcom (AVGO)	December 2018	4.8%
America Movil SAB de CV ADR (AMX)	December 2018	4.01%
Edison International (EIX)	December 2018	3.87%
Chunghwa Telecom (CHT)	December 2018	3.38%
Nokia (NOK)	December 2018	3.37%
Dollar Tree (DLTR)	December 2018	3.11%
BHP (BHP)	December 2018	3.07%
AutoZone (AZO)	December 2018	2.98%
Teck Resources Ltd Class B (TECK)	December 2018	2.3%
Banco Bradesco S/A ADR (BBDO)	December 2018	2.29%
KB Financial (KB)	December 2018	2.09%
HDFC Bank Limited ADR (HDB)	December 2018	2.09%
NRG Energy (NRG)	December 2018	1.9%
ICICI Bank (IBN)	December 2018	1.88%
Telefonaktiebolaget LM Ericsson B ADR (ERIC)	December 2018	1.72%

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