You can currently swap any of the following tokens:
AMPL
ANT
BAT
BNT
BTU
cDAI
CEL
DAI
ELF
ENJ
ETH
EURS
GEN
GNO
JRT
KNC
LINK
LMY
LRC
MANA
MATIC
MKR
NMR
PAX
pBTC
POE
POWR
REN
REP
RLC
RSR
SNT
SNX
sUSD
TUSD
UBT
USDC
USDT
WBTC
ZRX
We will progressively expand the number of tokens available to swap - feel free to suggest the ones you would like to see.