Marex Spectron publishes a range of proprietary indices on key European and Canadian energy markets.


The European gas and electricity indices have been published since 2001 and can be reviewed below. For information on the Canadian Crude Oil Indices, please click on this link


Indexes Contract Deal Date Total Volume High Low Average
U.K Power BSLD All-Day W/End WkEnd 16 Mar/17 Mar 19 15-Mar-19 45,600 43.400 43.200 43.279
U.K Power BSLD 8-12 W/End WkEnd 16 Mar/17 Mar 19 15-Mar-19 0 0.000 0.000 43.279
U.K Power BSLD All-Day D.A 20-Mar-19 19-Mar-19 3,600 44.250 44.250 44.250
U.K Power BSLD All-Day M.A 19-Apr 19-Mar-19 43,200 43.950 43.700 43.892
U.K BSLD All-Day M.A Cumulative 19-Apr 19-Mar-19 660,240 48.150 43.550 46.091


The All-day UK Power indices are calculated from the volume-weighted average of all Day-ahead and Month-ahead Baseload trades done during the course of the day. All times are British Standard Time (BST), as determined by Marex Spectron. These indices are published at 18:00 hours each day.

Day-Ahead Index

The Day-ahead index is calculated using the volume-weighted average of all Day-ahead trades executed through Spectron. The index values power for delivery on the next day following the deal date. The index date is the delivery date e.g. the index published for 16 November 2006 is based on all Day-ahead trades executed on 15 November 2006.

Month-Ahead Index

The Month-ahead index is calculated using the daily volume-weighted average of all Month-ahead trades executed through Marex Spectron. The Month-ahead index values power for delivery in the month following the month in which the deal is executed. The index month is the delivery month and the index date is the deal date e.g. the index for the 16 March 2016 is for all trades executed up to 6 pm on that day for power being delivered every day in the month of April. The index is published every UK working day.

Month-Ahead Cumulative Index

The Month-ahead Cumulative index is calculated at the end of each month using a volume-weighted average of all Month-ahead trades executed through Marex Spectron during that month.

Weekend-Ahead Indices and Bank Holidays

Weekend-ahead and bank holiday indices are also published. The index day(s) is/are the delivery day(s), however the trade execution day is not strictly the previous day to the delivery day, i.e. for a standard week the Weekend and Monday indices are both calculated using deals executed on the Friday, but at Easter four indices will be published from trades concluded on the Thursday – for the Friday, the Weekend, the Monday and the Tuesday. UK bank holidays are treated as individual days separate from the weekend.

Contingent Methodologies

Should the number of trades executed in a day be:

Five or greater - the index will be calculated using a weighted average of those trades.

Between one and four - the index will continue to be calculated using a weighted average of those trades. However, it will be noted on the index page that the calculation has been based on less than five trades.

Zero - the following contingent methodology shall apply:

For Day-Ahead

The index shall be derived from market discussion/ assessments.

For Month-Ahead

The index shall be calculated using the closing market price published in Marex Spectron’s daily market summary Spectrometer.

Index Out-Turns

Monthly index out-turn values, calculated from the average index value over the course of a month, will be published for both Day-ahead and Month-ahead indices, as these are commonly used for contract benchmarking.


Should there be subsequent changes to the source data used to calculate the indices, then the index shall be recalculated and republished automatically i.e. the index shown within the historical indices tool is the most up to date calculation of the index (amended indices are flagged as such within this file.


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