There are lots of reasons why most havent heard of these behemoths previously. Some have a regional focus dedicated to operations in far-flung markets across the world, whilst some work solely in highly specific niche industries.
Real Business has unearthed five companies that have so far remained shrouded in obscurity, despite being valued extremely highly, and that you are likely never to have heard of.
(1) Saudi Aramco
The worlds most important energy producer and overall largest company is state-owned Saudi Aramco, controlling Saudi Arabias 321bn barrels of proven oil and gas reserves.
Originally founded in 1933 when the Standard Oil Company of California was granted the right to explore and dig in Saudi Arabia for 60 years by King Ibn Saud, the company was controlled by American firms for decades. In 1980, the Saudis nationalised the company entirely.
In January this year, the Saudi monarchy indicated that Saudi Aramco could imminently open itself up to outside investors in a share sale. Not wanting to give too much away, deputy crown prince Muhammad bin Salman told reporters: This is something that is being reviewed, and we believe a decision will be made within the next few months.
Whilst by no means an uncompromising promise, the sheer size of Saudi Aramco makes any inkling of a share sale interesting, as it would almost certainly become the worlds most highly valued company with a market capitalisation of more than $1tn.
By comparison, the worlds current largest publicly traded oil company, Exxon Mobil, with roughly 25 billion barrels of proven oil and gas, is valued at around $320bn. Saudi Aramco has ten times the amount of oil.
In June 2012, this Chinese smartphone manufacturer the fifth largest worldwide was worth a little over $4bn. Fast forward a few years and, following a significant funding round, the company is now valued at around $45bn thanks to a strict company policy of tight profit margins and locally-focussed consolidation.
Xiaomi has famously yet to start marketing its brand in the west, which is probably why youve never heard of it, and concerns surrounding the patent wars that have dogged many other smartphone manufacturers in Europe and the US mean it may be unlikely to in the near future.