A somewhat tangential question that I'm genuinely curious about: Would anyone happen to know why the New York media always puts the periods in I.P.O. and I.B.M.

A somewhat tangential question that I'm genuinely curious about: Would anyone happen to know why the New York media always puts the periods in I.P.O. and I.B.M. and presumably N.Y.T. too? It's so different from what I'm accustomed to, and seems to definitely be a New York thing. Everywhere else it would be IPO, IBM, and NYT. So why does the N.Y. media do this?