NPR
Which brings us to the bond that broke the internet: The Series I Savings Bond. These are government bonds that are adjusted for inflation and are paying an annualized interest rate of more than 9.6%. The deadline for locking in that rate was Friday, October 28 (after that rates dropped to around 6%): Hence the crashing website.
TikTok, Instagram and YouTube have all been filled with financial advisors instructing people to go to the Treasury's website ASAP and buy the bonds.