Sun Life Financial Inc. (SLF) is the holding company of Sun Life Assurance Company of Canada. The company is a financial services organization providing a range of protection and wealth products and services. It operates in five segments: Sun Life Financial Canada (SLF Canada), Sun Life Financial United States (SLF U.S.), Sun Life Financial Asset Management (SLF Asset Management), Sun Life Financial Asia (SLF Asia) and Corporate. SLF Canada has three main business units: Individual Insurance & Wealth, Group Benefits and Group Retirement Services. SLF U.S. has three business units: Group Benefits, International and In-force Management. It is reporting earnings on Wednesday, August 10, after market close: As evident from the above, the company beat earnings estimates in 75% of time in the last eight quarters, underperforming or showing in-line results in the rest of time, and has seen modest volatility in the market price of its stock over the last three months: The market participants expect the following numbers over the next few quarters, including the upcoming one: (Source: TD Waterhouse)Market data show that the August options are a bit undervalued: (Source: TD Waterhouse)The two-week straddles (options with a strike price of $30.00 and expiring on August 19, 2016) are worth around 1.1% of the current market price of the stock. Historically, the stock has been more volatile than that on a monthly basis over the last year: (Source: Google Finance. Calculations by author)As you can see, the stock has had a monthly standard deviation of 7.7% over the last 52 weeks, while the straddle expiring in a bit less than two weeks has an implied monthly volatility of around 4.7% (calculated based on 8 business days remaining until expiration), also including volatility from the earnings event this week. I therefore see signs of modest undervaluation in these options. Hence, buying the straddles is a good idea from a theoretical standpoint.Investors may also be interested in selling calendar spreads to capitalize on the higher implied volatility of the front month's options: (Source: optionsprofitcalculator.com)The risk-return profile of this trade looks like this: (Source: optionsprofitcalculator.com)As you can see from the above illustration, the "window of safety" is around 15.5%. This means that the stock has to move roughly 8% in either direction from the current price by expiration in order for investors to start losing money. The risk-reward ratio of around 1:2.67 is in line with this type of option strategies and is deemed attractive in the case of a low volatility stock like Sun Life Financial Inc.