Asia's naphtha physical crack surged by another 145% on Monday to reach a near two-and-a-half-week high of $32.20 a tonne, supported by strong demand and improving gasoline fundamentals.

The surge in crack followed a 1000% spike from the previous session after the value plunged into the negative zone on Thursday for the first time since April 20.

"Thursday's drop was weird," said a Singapore-based trader, adding that the fall was an over-reaction to cargoes coming in from the West, including Europe.

More than 2.2 million tonnes of naphtha from the Europe, the United States and Africa are expected to arrive in June, making this the fourth time this year when volumes surpassed the 2 million mark, or more than 30% above 2019's monthly average.

But demand for naphtha feedstock to make petrochemicals has been strong, and traders expect this to mop up some of the excess supplies.

With lockdowns gradually easing in some parts of Asia, traders expect better demand for gasoline, which also uses naphtha as a blending component.

India's HPCL offered 30,000 tonnes of naphtha for end May loading from Vizag in a tender closing on May 19.