TORONTO (Reuters) - A see-saw session on the Toronto Stock Exchange on Friday saw the the main index slump to hit a four-year low and then bounce back in a late-session rebound that could lead to a strong opening on today.

But market players are nowhere near confident enough to forecast any sustained rally.

Traditional market logic says late-week gains foretell a positive start to the following week. Based on that, the TSX composite index should be set to get off the mark relatively well today, after rallying from a near 700-point deficit early Friday to close just shy of break-even.

The index ended the session down just 37.26 points at 9,294.09, after touching its lowest point since late 2004.

However, the hair-trigger nervousness of market players means any progress could be swiftly derailed by weak corporate earnings, further signs of a global recession, or concerns that additional corporate failures could be on the horizon.

"Valuations have been beaten down extremely to bargain basement levels, which means one of two things," said Elvis Picardo, strategist at Global Securities in Vancouver.

"It either means that, at some point, investors take comfort and start getting back, or that what's on the horizon is something much worse than any of us has ever seen before."

Such uncertainty among market professionals has been the norm in the past few weeks as the TSX has set records for both daily losses and daily gains, moving in huge swings, but with a general downward push.

"People are searching for a bottom in both the Toronto and New York markets, and it's anyone's guess whether it was Friday, whether it's going to be Monday, or Tuesday," said Bruce Latimer, a trader at Dundee Securities.

Traders who have managed to survive the recent market carnage with their jobs and sanity intact will be watching news feeds over the weekend for major earnings misses or signs of more corporate failures that could further spook already nervous markets. Analysts say the latest hiccup for investors may come from quarterly earnings and corporate forecasts that will come in below expectations.