After jumping to almost $63 a barrel on Monday, Brent crude slid back to not much over $60 after Saudi Arabia's oil minister said OPEC would not cut production at any price.
The stabilisation of oil prices was a major factor behind Gulf bourses' recovery since late last week, so the possibility of oil again testing $60 means equities' upward momentum looks set to fade.
Although most markets rose on Monday, their gains slowed and turnover, while still active, fell from Sunday's high levels - signs of waning momentum. The recent rebound has not turned markets technically bullish, as they remain below downtrend lines and 100- and 200-day averages.
Saudi Arabia's index edged up 0.3 percent on Monday to 8,547 points; it faces technical resistance around 8,700 points, where its downtrend line from September now comes in.