De or het topholding?

The correct Dutch article is:

de topholding

Rule Words ending in -ing: almost always de. See the rule

How to use topholding

the topholdingde topholding
this topholdingdeze topholding
that topholdingdie topholding
our topholdingonze topholding
your topholdingjouw topholding
every topholdingelke topholding
which topholding?welke topholding?
a big topholding / the big topholdingeen grote topholding, de grote topholding