Who Wants to Be a 401(k) Millionaire?
— Matt Heimer (@MatthewHeimer) November 12, 2013
The last paragraph of the MarketWatch article sums it up (the keyword here is “assuming”):
Given that today’s crop of 401(k) millionaires benefited from the long bull market that stretched from 1982 to 2000, how likely is their experience to repeat? Fidelity calculates that someone who earns $40,000 a year and starts saving at age 25 will have $1 million by age 67, assuming he or she receives 1.5% annual raises, saves 16% a year, and earns a 7% annual return.