Mergers and acquisitions have hit $4 trillion this year, on track for a record annual deal value - and Goldman Sachs is the big winner so far.
After Visa 's $23.3 billion offer for Visa Europe, announced on Monday, the value of announced deals now stands at $4.06 trillion in 2015, Dealogic data shows, up from the previous, pre-credit crisis high of $3.93 trillion at this point in 2007.
Strategists at UBS warned last week that activity is now "feverish". And after some fevers there comes a cold sweat, as investors found in 2007.
"The announcement of talks between Pfizer and Allergan is reminiscent of deals such as AOL /TWX in 2000 and RBS/ABN-AMRO in 2007, blockbusters in market leading sectors which were followed by major market tops," they wrote in a research note which suggested that the end of the bull market was approaching.
An explosion in cheap credit fueled by the extraordinary monetary policies pursued by major central banks, tax planning and increased confidence in certain parts of the global economy are all contributing to the boom.
Health care and technology, both sectors which have had their problems in recent years, are by far the biggest sectors for deals this year.
"It's very much an eat-or-be-eaten environment (in pharma) at the moment," Jamie Davies, head of pharmaceuticals, medical devices, and health care at BMI Research, told CNBC.
"They're looking for the next thing and M&A seems to be what they've latched on to."
This time round, the M&A frenzy is being fueled by fewer deals, but with bigger price tags. The number of $10 billion plus deals is 40 percent higher than at the same time in 2007.
This could mean a bumper bonus season for bankers in the M&A space next year. Goldman Sachs currently leads the rankings of M&A advisors, giving advice on deals worth $1.39 trillion so far, followed closely by JPMorgan and Morgan Stanley .
The trend may yet continue into next year, with 59 percent of global companies planning an acquisition in the next year, according to research from Ernst & Young. With M&A cycles historically tending to operate in three-year clusters, and the current boom kicking off in 2014, this suggests 2016 could be another big year before the inevitable bust.
- By CNBC's Catherine Boyle