不过，确实出现了一个重大问题。

One major problem did present itself, though.

《牛津词典》

根据一项调查，学生的安全已经成为一个重大问题。

According to a survey, students' safety has become a big problem.

youdao

如何保持可持续发展是所有国家面临的一个重大问题。

How to maintain sustainable development is a matter of significant importance facing all countries.

youdao

So the survivorship bias and the backfill bias would be much,much more of a problem in the hedge fund world.

所以生存偏差和回填偏差,会是对冲基金领域里一个相当重大的问题

耶鲁公开课 - 金融市场课程节选