The Bunker Review was contributed by Marine Bunker Exchange (MABUX)
MABUX World Bunker Index (consists of a range of prices for 380 HSFO, VLSFO and MGO in the main world hubs) continued downward movement on May 21:
380 HSFO: USD/MT – 412.66 (-3.35)
VLSFO: USD/MT – 10.46 (-4.39)
MGO: USD/MT – 608.07 (-2.45)
MABUX ARA LNG Bunker Index, available from April 29, 2021 and calculated as the average price of LNG as a marine fuel in the ARA region, fell slightly on May 21 down to 606.48 USD/MT (-0.74 USD). The LNG Bunker Index exceeds the price of MGO LS at the Port of Rotterdam by $ 85.48 (521 USD/MT as of May 21). More LNG Bunker Indexes on www.mabux.com.
As of May 21, a correlation of MABUX MBP Index (Market Bunker Prices) vs MABUX DBP Index (Digital Bunker Prices Benchmark) in four largest global hubs showed that 380 HSFO fuel stayed undervalued at three selected ports: from minus $ 16 in Fujairah to minus $ 38 in Rotterdam and minus $ 51 in Singapore, while, according to MABUX DBP Index, the price of 380 HSFO fuel in Houston returned back to overcharge sector: plus $ 2.
VLSFO, according to the MABUX DBP Index, was undercharged at three selected ports ranging from minus $ 20 in Rotterdam to minus $ 43 in Singapore. The level of underestimation decreased slightly. The only port where MABUX DBP Index still shows an overprice of this type of fuel is Houston (plus $ 22).
MGO LS, according to the MABUX DBP Index, remained undercharged in all selected ports, ranging from minus $ 12 in Houston to minus $ 56 in Rotterdam, minus $ 44 in Singapore and minus $ 55 in Fujairah. All in all, as per May 21, the underpricing margins of all bunker fuel grades narrowed slightly in four selected ports. 
We expect global bunker prices may rise slightly today: 380 HSFO may up by 7-10 USD/MT, VLSFO – by 9-12 USD/MT, MGO LS – by 2-7 USD/MT.
Source: www.mabux.com