Close a zero position if the market

[RMSSC]

Hello,
Is there a rule that allows me to close a zero position if the market moves against me?
Example:
Initial bet: Lay at 2.5 with $10
If the odds drop to 1.7
Close the bet: Back at 1.7 with $21.43

[Dallas]

Use a Back bet rule with the staking method 'By Liability (back & lay)'

[RMSSC]

Thanks Dallas