Three things to watch for in the markets on Thursday, including the earning season's busiest day

Jonathan Golub of Credit Suisse weighs in on earnings season

Here are the most important things to know about Thursday before you hit the door.

1. Busiest day of earnings

45 S&P 500 companies report quarterly results on Thursday, making it the single busiest day of the earnings season.

So far 124 companies in the index have reported. Eighty-two percent of them have topped EPS estimates and 63% have topped revenue expectations, according to estimates from Refinitiv.

All eyes will be on Amazon as investors look for an update on AWS growth as Microsoft and Alphabet also ramp up their cloud operations.

Shares of the tech giant have shed 12% over the last three months as an increase in spending and looming tech regulation have pressured the company.

Analysts are expecting EPS of $4.59 and revenue of $68.8 billion, according to estimates from FactSet. That's about 20% higher than the $56.58 billion in revenue that the company reported for the same quarter a year earlier.

"We expect strong topline momentum led by 1-Day shipping initiatives, a healthy consumer spending backdrop and strong growth in AWS and advertising," Stifel analyst Scott Devitt wrote in a note to clients.

But the momentum doesn't come without a cost. He's anticipating the company will earn $3.35 per share for the quarter — well below consensus estimates — although his revenue prediction of $69.5 billion is ahead of the Street.

Visa, Intel, 3M, Gilead, Alaska Air, American Airlines, Northrop Grumman and Twitter are among the names also reporting earnings Thursday.

2. Farewell Mario Draghi

The European Central Bank will announce its monetary policy decision tomorrow. Following last month's interest rate cut and stimulus measures, economists aren't expecting any fireworks at the meeting.

"We do not expect the meeting and press conference to generate new insight on the monetary policy outlook. With last month's decision, the direction has been set and the recent data, while very weak, was not bad enough to trigger further dovish monetary policy tweaks," UBS economist Reinhard Cluse said in a note to clients dated October 14.

But the meeting is important in that it's the last for president Mario Draghi. After heading the Central Bank for 8 years, he will step down on October 31. Christine Lagarde, who previously led the IMF, will take over.

Separately, we'll get manufacturing data from the Eurozone, as well as U.S. durable goods and new home sales data.

3. Pence on China

Vice President Mike Pence is scheduled to speak at an event organized by the Wilson Center. According to the think tank, the speech is expected to center on the future of United States and China relations.

President Donald Trump said earlier this month that the U.S. had come to a "very substantial phase one deal" with China, and that phase two discussions would start "almost immediately."

But there seems to be some confusion about what "deal" actually means.

Following the negotiations Chinese state media said that "substantial progress" had been made, but they did not call it an outright deal. More recently, sources told CNBC's Kayla Tausche that more talks are "likely" for phase one of the deal.

On Wednesday Senator Marco Rubio told CNBC that he doesn't think a deal has been made.

"If you look at the statements that have come out, it's been very difficult to get the Chinese to admit that they agreed to what has been reported they agreed to," he said on CNBC's "Squawk Box."

- CNBC's Michael Bloom contributed reporting.

Major events (all times ET):

4 a.m. Eurozone manufacturing PMI

4 a.m. Eurozone services PMI

7:45 a.m. ECB rate decision

8:30 a.m. ECB news conference

8:30 a.m. US jobless claims

8:30 a.m. US durable goods

10 a.m. US new home sales

Major earnings:

3M (before the bell)

Comcast (before the bell)

Dow (before the bell)

American Airlines (before the bell)

Hershey (before the bell)

Southwest Air (before the bell)

Tractor Supply (before the bell)

Twitter (before the bell)

Amazon (after the bell)

Gilead Sciences (after the bell)

Intel (after the bell)

Visa (after the bell)

Alaska Air (after the bell)

Capital One (after the bell)