ARCA BIOPHARMA Inc ARCA biopharma Inc Hall ARCA BIOPHARMA Inc ARCA BIOPHARMA Inc CO 3/1/2006 ARCA biopharma Inc ARCA biopharma Inc CO 9/25/2008 1 1 1 3 0 1
ARCA BIOPHARMA Inc ARCA biopharma Inc Hall ARCA BIOPHARMA Inc ARCA Biopharma Inc CO 2/3/2003 ARCA biopharma Inc ARCA biopharma Inc CO 9/25/2008 1 1 1 3 0 1
This is because there aren't multiple variants - just multiples of the same variant. It happens when there are two records for one company with the same state but different datefirstinv dates. One solution is to build an exclusion list of portco keys (those with the coname, statecode, and min(datefirstinv)) and exclude those keys everywhere applicable. Instead we went back to the original portco table and fixed it properly so that companybasecore doesn't have this issue.
3134 IPOs, of which 2551 are all good (3 out of 3), 495 have bad dates or states, and 87 are left. For these 87, almost all are pairs (presumably the ones that aren't had a bad date) where there are two issue dates and we should take the minimum issue date.