The worst price gaps always happen in asia session and always point to a selling bout for some few days or weeks.
Looking at the behaviour of Nikkei and HSI today, the morning session had huge price gaps and by the time the markets closed, all the gaps had been filled closing the day with very nasty dark candlesticks. Expect selling for a few days this week across board.
$15/barrel oil... The commodities lehman moment arrives as well as Sovereign debt volcano!