As far as reliability goes, consider that PM are a very new thing, so I recommend you use precaution with all of them for the time being.
Augur is working but last time I checked transaction fees were pretty high, so volume/liquidity was very small, it should improve in the near future especially if Ethereum transition to PoS (I also plan to start trading on Augur).
I heard you can sometimes trade events on sites like BetFair.
Other current/upcoming Predicion Markets not limited to the U.S. are:
As far as reliability goes, consider that PM are a very new thing, so I recommend you use precaution with all of them for the time being.
Augur is working but last time I checked transaction fees were pretty high, so volume/liquidity was very small, it should improve in the near future especially if Ethereum transition to PoS (I also plan to start trading on Augur).
I heard you can sometimes trade events on sites like BetFair.
Other current/upcoming Predicion Markets not limited to the U.S. are:
Gnosis
poly.market
Omen
FTX
Guesser