That is a lot. Was it an assisted hatch? My poult's was just a small thread, but it was enough to keep the abdominal wall from closing. Once it is completely dry, it can be snipped off close to the abdominal wall to prevent snagging/biting. It may be absorbed as the chick grows. They have...
Be sure not to pull on it, or let other chicks pull on it, or the intestines will come out. I had that happen with a poult last year and I had to euthanize immediately.
Are you certain it is yolk (yellow with blood vessels) or the sac that wastes store in while the chick develops?
The yolk is more critical, as it is usually absorbed before hatch is complete, and because it is covered with blood vessels, which, if broken, can bleed the chick out quickly.
If...