Not sure, but my DD just had the same issue. She actually called me from a party lol, I guess she had gotten a credit karma alert or something and was all concerned about it. I figured hers might be from utilization. She just got her new CC, but the limit is only $1000. She has been paying it early, but even with just a few hundred on there, her utilization will go way up. A few months ago I had dropped my limit on a new card to $5000, then immediately put $3000 on it to get my bonus. Didn't even think about it, but for 2 weeks my score dropped over 25 points and went right back up after I paid it off.