This is insane, 3.26% of Open interest in Bitfinex exchange are shorting bitcoin right now. This is extremely low as you know it is a ratio. It can not go below zero it can just be near zero. This is -in my opinion; an indication of extreme optimisim and will probably result in a powerful long squeez. To get this chart use this formula:
BITFINEX:BTCUSDSHORTS/(BITFINEX:BTCUSDSHORTS+BITFINEX:BTCUSDLONGS)*100
BITFINEX:BTCUSDSHORTS/(BITFINEX:BTCUSDSHORTS+BITFINEX:BTCUSDLONGS)*100