Despite a rocky performance for stocks in recent weeks, Wall Street has remained level-headed, sticking to predictions through the end of the year and encouraging clients to stay the course.

That doesn’t mean, however, that investors are worry-free. In recent days, strategists at top banks including Citigroup and JPMorgan have pointed to dark clouds on the horizon, noting that some may need to dissipate before riskier assets like stocks can move much higher.

“The Street generally dislikes uncertainty and therefore we sense a desire from fund managers to get a better ‘feel’ for these items before committing to equities for next year,” Tobias Levkovich, Citi’s chief US equity strategist, said in a recent research note.

On the list: Levkovich pointed to four main issues investors want resolved.

  • The outcome of the US election in November.
  • Whether there will be more government stimulus — and if so, when.
  • Whether effective vaccines can be distributed in early 2021.
  • If stocks can still attract new buyers.

On that last item, Levkovich notes that US households’ ownership of stocks as a percentage of financial assets is near 50-year highs, and that foreign investors are already very exposed. While mergers and “blank check” acquisition companies could scoop up some stocks that have fallen out of favor, “it is hard to identify the new source of money that can drive up share prices presently,” Levkovich said.

JPMorgan’s John Normand, meanwhile, reminded clients on Friday that the size of Big Tech firms compared to the overall market means any weakness in tech stocks poses an enormous risk, even after the dramatic correction that occurred last week.

Apple shares have dropped 14% since reaching an all-time at the beginning of the month. But at $1.97 trillion, the company’s market value remains close to that of the entire FTSE 100 index in London.

JPMorgan sees the election and the US fiscal debate as major headwinds, too. Looking abroad, the bank is also watching Brexit negotiations, the path of the virus in Europe, as cases spike in countries like France, and the relationship between OPEC and key allies.

“It will be difficult for markets to retain much upward momentum until these issues clear,” Normand said.