Flat week for STI, Yellen's speeches the main focus

US Federal Reserve chair Janet Yellen's testimony on the state of the US economy did not reveal anything new, but it did present a very tradeable play for those brave and nimble enough to try their luck.

Increasingly, as the interest in penny stocks fades in the wake of an official probe into possible breaches of the Securities and Futures Act involving several small-cap companies, the Straits Times Index has come front and centre; it weakened in the early part as last week's month-ending "window-dressing" was reversed, then bounced up ahead of Ms Yellen's comments on Wednesday and Thursday.

In yesterday's session here, the index gained 4.44 points at 3,252.13, bringing its loss for the week to just 0.42 point. Turnover, however, has been poor throughout; after the April 30 window-dressing brought a spike up to $1.6 billion, yesterday's volume at 1.7…