In most coin sales, the coin hasn't even been developed yet. Look at Ethereum. They sold $18M worth of coins, then developed the coins, decided to delay release fearing that the Ether price would plummet since BTC was in a huge decline, then eventually let them go.
Fast forward to today and people want their coins before the coin sale ends.
Bittrex is hosting the BRX coin sale. The BTC-BRX market will not open until after the coin sale has completed.