With a quarter of a million employees, a market capitalization of nearly $200 billion (176 billion euros) and one of the world's most prominent advertising campaigns, HSBC is hard to miss.
While its brand is splashed across billboards and airports around the world, its reputation has been tarnished in recent years by a string of high-profile controversies.
Allegations emerged on Monday that HSBC's Swiss private bank division helped rich clients avoid millions of dollars in tax after an employee, Hervé Falciani, stole secret files in 2007 and turned whistleblower.
In 2012, HSBC agreed to pay out $1.92 billion to US authorities for oversight failures which meant Mexican drug traffickers could launder money through its accounts and banned transactions took place from Iran.
Last year, it was charged with manipulating a key inter-bank lending rate by the European Commission.
Its foreign currency traders were also implicated in a scheme to make money by rigging markets uncovered by Britain's Financial Conduct Authority last year.
"There is a deliberate strategy by the bank to appeal to wealthy clients around the world, particularly in Asia, where HSBC has a major presence in Hong Kong and Singapore," said Maxime Mathon, a spokesman for Paris-based equity research house AlphaValue.
Vast global reach
The financial behemoth is headquartered in one of London's tallest buildings, a vast skyscraper in the ultra-modern Canary Wharf office district.
But that belies its history, rooted in the British empire of the 19th century.
The Hongkong and Shanghai Banking Corporation Limited was set up in Hong Kong in 1865 by Thomas Sutherland, a Scotsman who saw a niche catering to local businesses.
It grew quickly across Asia, North America and Europe, becoming one of the world's major banks by the end of the 20th century.
It now has some 50 million clients in 74 different countries around the world.
Like most globalized banks, HSBC has a whole range of different operations, from high street retail banking to trading on global money markets and private banking, which helps some of the world's richest people make the most out of their money.
Since the 2008 financial crisis, attitudes have changed to what is permissible for banks to do in pursuit of the highest returns for their clients, experts say.
"This HSBC story is a legacy of what did exist in private banking before the financial crisis and that the governments around the world don't want to exist any more," said Arun Melmane, an analyst at investment bank Canaccord Genuity.
"These are offences but they were quite overlooked at that time by a lot of jurisdictions due to Swiss secrecy."
HSBC's Swiss banking arm insists it has undergone a "radical transformation" since 2008 to stop its services being used to evade taxes or launder money.
"Swiss private banking nowadays is not about saving taxes but about managing people's money," Melmane said.