As investors carefully scan an uncertain horizon, one thing is clear: The backdrop for markets will look very different in three months’ time.

In a note to clients this week, Goldman Sachs strategists including Kamakshya Trivedi predicted a “substantially different landscape” by December.

They pointed to three potential developments:

  • We’ll know the results of sending kids back to school this fall.
  • The US election will be behind us.
  • A Covid-19 vaccine could be on the “verge of approval.”

On reopening schools, Goldman Sachs expects a “bumpy process” characterized by “some false starts,” especially in the United States. That could hang over markets, particularly in September.

“The evidence so far suggests that there is a path to reopening schools without prompting a sharp increase in virus spread,” the investment bank said. “But those examples have generally been in places where transmission has been very low and where strict protocols have been followed.”

The passage of the US election will also provide investors with greater clarity, particularly regarding the relationship with China. Goldman Sachs thinks that decoupling between the world’s two biggest economies is poised to continue no matter who wins, though Joe Biden would be less likely to employ tariffs.

Most importantly, Goldman Sachs thinks there’s a “good chance” that at least one vaccine will be approved by the US Food and Drug Administration by the end of November, allowing it to be “broadly distributed” by mid-2021.

“This kind of timeline could see a substantial boost to GDP relative to a ‘no-vaccine’ case, particularly for the US, which is likely to lead the vaccine race and is likely to experience worse outcomes than in Europe without a vaccine,” the bank’s strategists said.

They predict the S&P 500 will end the year around current levels, but see the potential for the index to shoot up another 11% if a viable vaccine comes into play.

What it means: The picture for investors is murky this summer, with little transparency on the path of the virus or upcoming rounds of stimulus spending. But Wall Street thinks some clouds could clear before year-end.

“We’re at a crossroads,” Thomas Lee, cofounder of Fundstrat Global Advisors told my CNN Business colleague Alison Kosik on Wednesday.

If it becomes evident that the virus has peaked in the United States and the surge of cases in the Sun Belt has been brought under control, investors should go on the offensive, he said.

Of course, nothing is a given. In three months, the situation also could look materially worse, with cases rising in new parts of the United States. There are also growing concerns about a second wave hitting Europe and Asia.