Roku, CVS Health earnings, productivity data: Three things to watch for in the markets on Wednesday

A video sign displays the logo for Roku, after the company's IPO at the Nasdaq Market in New York, September 28, 2017.
Brendan McDermid | Reuters

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

1. Will Roku rally on earnings?

Roku reports third-quarter earnings after the bell on Wednesday. RBC Capital Markets is expecting revenue of $254 million, at the high-end of Roku's guidance between $250 million and $255 million, and slightly below Wall Street's estimate of $257 million. RBC is expecting a GAAP loss of 32 cents, after a loss of 9 cents in the same period last year.

Roku shares cratered in September after Comcast announced a new deal for cord cutters and Facebook unveiled a new device that can stream TV shows. RBC said it will be listening for management commentary about the potential impact the streaming wars have on Roku.

Shares of Roku are still up more than 350% this year.

2. CVS Health set to report

CVS Health will report third-quarter earnings before the bell on Wednesday. Deutsche Bank is expecting CVS to earn $1.79 per share on revenue of $63.12 billion. This compares to the $1.73 per share on revenue of $47.3 billion reported in the same quarter last year. CVS raised its full-year 2019 guidance in the second-quarter to a range of $6.89 and $7 per share.

"We will also be listening for reimbursement trends in the pharmacy as well as any impact from drug pricing changes," said Deutsche Bank research analyst Georgia Hill in a note to clients.

Shares of CVS Health are up nearly 25% in the past three months.

3. Productivity data

We'll get a preliminary read on U.S. worker productivity in the third-quarter. Economists polled by Reuters are expecting productivity growth to have continued slowing in the third quarter, estimating a rise 0.9% in Q3. Nonfarm productivity, which measures hourly output per worker, increased 2.3% in the second quarter, the Labor Department said. This was down from the first quarter's 3.5% rate.

Major events (all times ET):

8:00 a.m. Chicago Fed President Charles Evans speaks

8:30 a.m. Productivity and costs

8:30 a.m. Unit labor costs

9:30 a.m. New York Fed President John Williams speaks

3:15 p.m. Philadelphia Fed President Patrick Harker speaks

6:30 p.m. NY Fed President John Williams speaks

Major earnings:

CVS Health (before the bell)

Humana (before the bell)

Roku (after the bell)

Square (after the bell)

Qualcomm (after the bell)

Fitbit (after the bell)

Fox Corp. (after the bell)

Disclosure: Comcast is the owner of NBCUniversal, parent company of CNBC and

—with reporting from CNBC's Michael Bloom.