COGENT COMMUNICATIONS HOLDINGS, INC. — 4/A Filings

All 10-K 10-Q 10-Q/A 144 144/A 3 3/A 4 4/A 424B3 424B4 424B5 424B7 425 5 8-A12B 8-A12G 8-K 8-K/A 8-K12G3 ARS CERTAMX CORRESP CT ORDER DEF 14A DEF 14C DEFA14A FWP IRANNOTICE POS AM PRE 14A PRE 14C PRER14A PRER14C RW S-1 S-1/A S-3 S-3/A S-3ASR S-4 S-4/A S-8 SC 13D SC 13D/A SC 13G SC 13G/A SC 14D9 SC 14D9/A SC TO-I SC TO-I/A SC TO-T SC TO-T/A SCHEDULE 13G SCHEDULE 13G/A UPLOAD