It was a big day for investors watching the race to create the next generation of hepatitis C drug cocktails. Most of the major players released data for the European Association for the Study of the Liver conference today.

In the segment below, health-care analyst David Williamson explains why small-cap Achillion has an uphill battle in front of it while attempting to dethrone big pharma and big biotech Goliaths. Watch and find out how Achillion disappointed investors today, but its real test is still ahead.