Two lucky premium bond winners became millionaires overnight after winning the jackpot in October's NS&I prize draw.
This time, the £1m prize went to one man and one woman - but are prizes always split equally between the sexes?
We've crunched the numbers on recent jackpot winners to show which group is the luckiest when it comes to premium bonds.
Which? also reveals the winners of the October prize draw.
Every month, NS&I hands out two £1m prizes to premium bond holders, with this month's prizes going to winners in Essex and Dorset.
The man in Essex holds £4,000-worth of premium bonds, which were bought back in August 1999 - more than twenty years ago. His winning bond number was 086KL514893.
A woman in Dorset bought the maximum £50,000 of premium bonds just two years ago in October 2017, winning with bond number 312TX505194.
While it's the seven-figure prize that most people dream of, millions of other prizes are won each month.
In October, NS&I awarded a total of 3,392,720 prizes, including six prizes worth £100,000, 11 worth £50,000 and 22 for £25,000. Another 58 people won prizes for £10,000, and 114 people won £5,000.
When it comes to winning the jackpot, it seems men might have a little more luck on their side.
Looking at records back to June 2014, of the 130 winners to bag £1m, 60 were women, 64 were men and six were undisclosed.
This isn't a very big difference - men are effectively 3% more likely to win - but it's interesting given the majority of premium bonds holders are women.
According to data from NS&I, there are 10.7m women who hold premium bonds - 51% of all holders. They also hold 51% of the total value of bonds, accounting for £42.2m.
A further 150,531 people were classified as 'other' or 'unknown'.
By comparison, there are 10.1m male premium bond holders, who have collectively invested £38.4m.
While it may see odd that men could then win more often, results like this are consistent with a having a random draw, in the same way that flipping a coin 10 times might turn up heads nine times.
In truth, there isn't much you can do to increase your chances of winning, as premium bonds prize draws are completely random.
The draws are conducted by 'Ernie' - a nickname for NS&I's Electronic Random Number Indicator Equipment.
Each £1 bond is given its own unique number, which is then matched against the random numbers generated by Ernie to choose that month's winners.
This means that every premium bond has an equal chance of getting picked - regardless of its date of issue (although you must have held them for a full calendar month following the month you bought them before they enter the draw).
More recent bonds tend to win more often because there are more of them in circulation. When the top prize was increased to £1m in 1994, people flocked to invest their savings in bonds.
It's important to note that premium bonds don't pay any interest on the money you invest.
The NS&I provides 1.4% figure as an average prize rate - that is, of the millions of people who have invested in premium bonds, the average growth their savings achieve is 1.4%.
This takes in people who won £1m, as well as the many people who haven't won anything.
If you hold £10,000 or more in premium bonds, you have a 99% probability of winning least one prize each year - but it's not guaranteed. Even if you do win a prize, it's most likely to be £25.
If you buy the minimum £25-worth of premium bonds, your probability of winning anything over the course of 12 months plummets to just 1.2%, as shown in the graph below.
Someone who invests the maximum £50,000 would need to win £700 a year to earn a 1.4% return.