Earnings season is still underway. Last week's top earnings stories in tech included big moves from The Trade Desk, Intuit, and Roku. And this week is sure to feature some more big swings.

Three stocks in particular that could see some volatility this week are Square (NYSE:SQ), Teladoc (NYSE:TDOC), and Workday (NASDAQ:WDAY). All three of these stocks have been on a tear this year, rising 38%, 36%, and 22%, respectively. With such sharp year-to-date gains, you can bet investors will be watching these companies' earnings reports closely.

A customer uses a chip reader built into Square Register.

Square Register. Image source: Square.

Square

Financial technology company Square is scheduled to report its fourth-quarter results after market close on Wednesday, Feb. 27.

For Square, the narrative to watch is undoubtedly revenue growth. The company recently reported its sixth quarter in a row of accelerating revenue growth. Square's top line soared 51% year over year during its third quarter, or 68% on an adjusted basis. Can Square keep growing its revenue so sharply?

For its fourth quarter of 2018, management guided for adjusted revenue between $445 million and $451 million, with the midpoint of this guidance range representing 59% year-over-year growth. Analysts, on average, expect revenue of $454 million.

Teladoc

Virtual-healthcare company Teladoc is also scheduled to report its results after market close on Wednesday. Investors will similarly look at the company's revenue growth, but will also pay close attention to total visits during the quarter, as this key metric helps investors gauge customer adoption of the company's services.

Management guided for fourth-quarter revenue of $119 million to $121 million, with the midpoint of this guidance representing about 56% year-over-year growth. Analysts' expectations for Teladoc's top line are in line with management's guidance for the metric.

Teladoc forecast member visits for the period to be between 720,000 and 820,000, up from 641,000 in the third quarter of 2018.

Workday

Enterprise cloud applications company Workday impressed investors when it reported its fiscal third-quarter results. Revenue and adjusted earnings per share both crushed consensus analyst estimates for the two metrics. Can the company keep up its strong momentum?

Workday investors should watch the company's subscription revenue, which accounts for about 84% of total revenue. The company's year-over-year growth in subscription revenue accelerated in its third quarter of fiscal 2019; subscription revenue rose 35% year over year -- up from 30% growth in Q2. Can subscription revenue keep growing so sharply?

Management said it expects its full-year fiscal 2019 subscription revenue to rise about 33% year over year, to between $2.375 billion and $2.377 billion.

Workday will release its fourth-quarter and full-year results after market close on Thursday, Feb. 28.