The STI has formed Wave 2 (brown), although it is uncertain that it is completed. It is typical that Wave 2 will retrace 61.8% of the length of Wave 1. Sometimes it is 50% or another Fibonacci ratio.
It is possible that the latest wave structure is corrective. Some analysts are predicting that a crash is round the corner, as has happened in several past Octobers. I am keeping the positive wave count for now. It will be invalidated if Wave 2 falls below the start of Wave 1 at 3040.16. If Wave 2 falls further below, say around 3000, the STI will have formed a double-headed head and shoulders pattern, which could bring it down to 2700 or lower! Frightening indeed!