A Wells Fargo analyst has noted that Apple has ceased to disclose its advertising spend in its latest 10-K annual report, instead bundling it into a more general category of ‘selling, general and administrative (SG&A) expenses.’ Apple has in the past always specifically disclosed its ad spend, notes Business Insider.

Apple last year increased its ad spend by a massive 50% to a record $1.8B. While the 10-K suggests that this year’s spend is lower by one measure, Wells Fargo suggests that might not be telling the whole story …

While SG&A expenses were down year-on-year on a dollar basis, S&GA expenses as a percentage of overall sales were up one percentage point to 7%.

Wells Fargo’s analysts also point out that Apple ended 2016 with its lowest operating margin since 2009, which could be in part due to Apple seeing less leverage — or in other words, spending more ad dollars to drive total revenue.

Put another way, Wells Fargo thinks Apple doesn’t want people to see that it’s having to work harder to maintain sales.

The research note is speculative, so there may be other explanations, but it does seem to be a logical one. Apple had not responded to request for comment at the time of writing.

You can follow iPhoneFirmware.com on Twitter or join our Facebook page to keep yourself updated on all the latest from Apple and the Web.