Apple has bought more than 20 companies since November, but we know about only 6 of them

Apple has acquired 20 to 25 companies in the past six months, CEO Tim Cook told CNBC on Monday.At that rate, the popular electronics company has bought a new company every two to three weeks.But most of those acquisitions have been kept on the down-low, and many from the past six months haven't been announced.Read more stories on the Business Insider homepage.Apple has bought 20 to 25 companies in the past six months, according to CEO Tim Cook, but you probably haven't heard about most of them. Cook's disclosure came during an interview with CNBC on Monday, in which he said the company mostly acquires for talent and intellectual property. He said that Apple buys a new company every two to three weeks on average.Among those 20-plus acquisition is Apple's December purchase of Platoon, a startup that works directly with musicians to produce and distribute their work. In March, Apple reportedly acquired a API development startup called Stamplay.But there are at least 14 Apple acquisitions unaccounted for. Given Apple's market cap of $952 billion, most acquisitions the company makes are too small to be materially consequential, which means Apple doesn't have to disclose its purchase or any information about the buying process.Here are the Apple acquisitions since November that we know about:Laserlike — a machine learning startup in Silicon Valley, that The Information reported was acquired in MarchStamplay — the API development startup acquired in March.PullString — a San Francisco startup for creating voice apps, that Axios reported was acquired in FebruaryDataTiger — a UK digital marketing startup that Bloomberg reported was acquired in FebruaryPlatoon — the music distribution startup acquired in DecemberSilk Labs — a startup that makes AI software “light enough” for consumer devices, according to the The Information reported the deal in NovemberThe company has $225 billion in cash and securities on its balance sheet, according to its most-recent earnings, which makes Apple is one of the most cash-rich enterprises in tech. It also means Apple has a lot opportunities and incentive to spend.But unlike tech giant IBM which spent $34 billion on Red Ha,t or SAP which spent $8 billion on its acquisition of Qualtrics, Apple historically hasn't bet the farm on big deals.Some of Apple's big acquisitions in the past include its $400 million purchase of Shazam in 2017 and its $3 billion acquisition of Beats in 2014, but M&A of that scope are few and far between.Do you know which 20 to 25 companies Apple acquired in the past six months？ We want to know more. Contact the author at bpeterson@businessinsider.com or DM her on Twitter if you have more information about Apple's M&A habits.