Huh? The network weight is ~26-27 million. Your math means only ~0.26-0.27 SIGT are being staked.
EDIT: Also, my weight is shown as the number of coins I'm holding.
The weight that is written in getstakinginfo command in console. The one in a hint is already converted)
But I'm not sure it's the staked coins exactly, this value is calculated from the last 72 PoS blocks (summ of all difficulties * 4294967296 / sum of all block times).
I think it should represent staked coins)) And your weight is an amount of mature coins multiplied by their age (in days I guess).