What happened

Shares of fast-food burrito maker Chipotle Mexican Grill, Inc. (NYSE:CMG) are down 6.9% at 2:25 p.m. EDT on June 20, following an SEC filing after-hours on June 19 from the company. In the release, the company disclosed a change in its guidance for expenses in the second quarter. According to the filing, Chipotle management anticipates marketing and promotion expenses will be approximately 20-30 basis points higher than in the first quarter, and would be 3.6% to 3.7% of sales in the quarter.

So what

For some context, this is a relatively small increase versus the full-year target for this line item. For the full year, Chipotle's guidance in its most-recent quarterly earnings report was 3.3% of sales. If the company sees its full-year sales and promotion expenses increased to the high end of its new guidance of 3.7% of sales for the full year, that would cost the company about $0.58 per share. That's about 18% of the company's $3.28 per share in earnings over the past 12 months.

A chipotle burrito with chips and guacamole.

Image source: Chipotle.

However, it's not clear that the company's full-year sales and promotion expenses are likely to increase by that amount. Management didn't change its full-year guidance, and also held firm on its expectations for food costs in the quarter.

Now what

Before Tuesday's big drop, shares of Chipotle had gained more than 20% since the beginning of 2016, and at one point in mid-May, were up as much as 30%. With strong gains so far this year, it's likely that Tuesday's "bad" news was enough to push some investors to sell in order to capture those gains.

CMG Chart

CMG data by YCharts

But from the long-term picture, Tuesday's announcement doesn't really change much about the thesis for Chipotle. Management has been steadfast that investing in marketing would remain an important part of recapturing mind share and bringing customers back, and those efforts have paid off with multiple quarters of growth in sales at restaurants open more than one year.

Put it all together, and for long-term Chipotle investors, Tuesday's sell-off should probably be viewed as an opportunity to buy, not a reason to sell. 

Jason Hall owns shares of Chipotle Mexican Grill. The Motley Fool owns shares of and recommends Chipotle Mexican Grill. The Motley Fool has a disclosure policy.