StockcountThere is no accountability for the indexThey buy when...

Stockcount
There is no accountability for the index
They buy when they have to match a relevant index
When WBT entered the ASX200 a large number of shares were purchased by the index funds at close of business at a price near $7
These were no doubt accumulated by brokers/investment banks prior to the balance date knowing the amount index funds would require
The index funds then lend their shares for a fee following this
By default this extra income ensures they will beat the index, even if only marginally
When they exit, say at a rebalance date they negotiate a price with buyers/ shorters at the close of business on rebalance date
Therefore by this process they have matched the index, plus a bit more from stock lending fees
You and I and other investors buy/ sell on different fundamentals
The whole thing may seem to be farciscal, but the victims are clearly not the index funds as they have no other accountability except to match the index