Here's the reason that pledges are still slowly going up:source
For who is unaware there is a grace period in effect, if you still want to buy a few ships now is the chance.
"During the last 48 hours of the pledge drive, the RSI servers were going up and down like a yo-yo. A lot of people have missed out on pledging because of this. Don’t worry though, CIG has your back! Sandi Gardner, Cloud Imperium Games’s Marketing Director, had this to say: “If you were unable to get on the site in the last 48 hours there is a short grace period. [...] If you tried to get on before the campaign closed then you should pay the correct prices so please email me [at] firstname.lastname@example.org and we will honor the insurance. [...] We want to make sure we take care of those who kept trying and couldn’t pledge.” She went on to say that they realized that a few people would sneak in, having learned about the pledging too late, but CIG would rather those that tried and missed out get their fair shot at a pledge than worry about anyone being a little less than honest. Ben Lesnick, Community Manager, further clarified that during the grace period, the limited time add-ons will be available. After the grace period, only the original ships (Aurora, 300i, Hornet, Freelancer, and Constellation) will be available as add-ons. Anyone who pledged during the drive or grace period will be able add the original ships, with all current benefits (including life time insurance) and at current prices after the grace period ends. The grace period ends at 00:00 (12:00am) Central US Time, Monday, November 26th – So make sure you get in by the end of Sunday! Keep an eye out for the official announcement about the grace period on the RSI website!"