How the BDI works
Every work day since 1985 1), ship traders and brokers alike have looked to a set of
indices provided by the Baltic Exchange in London to get a feeling for where the
market is moving and how to conduct their business accordingly. The central indicator
among the bulk carrier indices, the Baltic Dry Index or BDI, gained new prominence
in the mainstream press in late 2008 as it was frequently cited by economic analysts as
the most honest indicator of “real economy” trade flows, linked, as it is, nearly
exclusively to the demand side of trade due to the relative inflexibility of the supply
side, i.e. total capacity of the world fleet. The world fleet capacity (“supply”) is
judged as comparatively inflexible and, thus, unchanged in the short term because at
least two years are needed to build a new ship. But few, even the most veteran of
shipbrokers, have anything but a superficial understanding of what is behind the BDI
and from what it is generated. To correct this lack of understanding is the goal of this
guide.
What is the BDI?
The Baltic Exchange’s signature bulk shipping index constitutes a single number, calculated
daily, albeit a single number constructed from multiple sources and layers of input, hiding in its
simplicity the complexity of the entire bulk carrier market. In efforts to portray the most
representative picture of the day’s dry bulk market, the value of the BDI is compiled from
broker-provided estimates of prevailing rates on a series of specifically defined trips (for instance
the charter rate for a 180,000t cargo on a modern Capesize vessel transiting from
Continent/Mediterranean to China-Japan range is designated as the C9_14 route). The Baltic
Exchange has defined 27 separate routes standard to the industry (including two test routes that
do not contribute to the BDI) covering three size classes – Cape, Panamax and Supramax. Since
2018 the Handysize class with its own seven standard routes is no longer included in the
calculation of the BDI but still reported apart. – All routes in turn are calculated into the four
individualized routes of the BCI, BPI, BSI and BHSI.
Where does the information come from?
Where does the Baltic Exchange get its “basket” of broker-provided rate estimates? These daily
ratings are provided to the Exchange every day by active shipbroking companies appointed to be
a “panellist” for the Baltic Dry Index. Among its prerequisites, the panellists, who send in their
rate estimates every day, are required to be (1) companies with their primary activity as
shipbroking, (2) recognized as competent, professional firms active in the market and with
sufficient staff to maintain the duties of a panellist, (3) members of the Baltic Exchange, (4)
adhere to a list of standard terms, (5) be selected as to maintain an “appropriate geographical
spread” of panellists, (5) not be exclusive representatives of charterers that have an overly
dominant influence in a particular trade route and (6) must nominate a member of the Exchange
as responsible for each respective index on which they report.
The BEX routes
Of the Baltic Exchange’s 34 active routes, seven are voyage rates and the remaining 27 are time
charter rates. All seven of the voyages are Capesize and Panamax rates and denominated as pertonne values. They are determined by panellists and designated by route. For example, the
Baltic’s C2 route – tracking a 160,000t freight on delivery from Tubarao and redelivery to
Rotterdam – is at this writing valued at 10.967 US$/ton, representing a close match to average
rates that have been chartered on that route in recent days. The Cape index, BCI, and the
Supramax index, BSI, have ten routes each, while the Panamaxes and the Handysizes account for
seven routes each. During the last years some changes have been agreed in regard to vessel sizes
and additional routes. Lest one think that the Baltic only tracks the spot market, it should be
known that the time charter values – starting with the C8_14 route for a modern 180,000 dwt
vessel on a trans-Atlantic trip delivery Gibraltar redelivery Hamburg – are calculated with a
combination of both spot and period values. Panellists, according to the Baltic, as “guidance” use
both sets of fixtures, simply dividing period deals into an average and incorporating their
calculations into their consequent assessments.
The Freight Indices and Futures Committee (FIFC) of the Baltic Exchange is responsible for
gathering freight information for the exchange and selecting the routes that contribute to the
generation of the BDI. Each route has been selected by the FIFC for geographic balance between
both the eastern and western routes as well as the trans-Atlantic and fronthaul routes. Emphasis
is also given to keeping a commercial balance between time charter and voyage assessments.
After panellist assessments covering each route are compiled daily for the four individual bulk
indices using a specific inverse factor to equalize a route’s impact – or multiplier – they are
combined with a pre-defined weighting number to produce the day’s value for the BDI.
The calculation of the BEX indices
Looking at the BCI, for example, it employs 10 different route ratings to come up with its
singular value. Since five of the Cape routes are voyages and the rest are time charter values, it is
important to normalize each value with a multiplier to put rates within a reasonably close range
and thus create a realistic average. The C2 route covering a Cape freight Tubarao/Rotterdam may
have a (per tonne) value of around 10-50 while the C8_14 covering trans-Atlantic time charters
would have a (per day) value in the thousands, e.g. US$ 10-50,000 daily. In order to put the
values into a common range, the C2 is pegged with a maximizing multiplier of 27.649, making a
C2 of 10 into 276.49. The C8_14, on the other hand, is minimized with a multiplier of 0.011395,
which makes a C8_14 of 10,000 into 113.95. Now, the two values, 276.49 and 113.95, are in a
reasonably close range and can, using multipliers, be averaged into a common value with the
other routes into the BCI.
In principle, these index values are then evenly weighted to calculate the BDI according to the
following formula which uses another multiplier:
((BCI + BPI + BSI)/ 3) *0.1
The multiplier was first applied when the BDI replaced its predecessor, the BFI in late 1999, to
enable a smooth transition and has since been changed several times as the other indices were
modified.
The BDI is, admittedly, an abstract number lacking a direct link to one single currency or single
freight rate, but as the summation of world market movements as a whole, there is perhaps no
better way to numerically visualize the day-to-day dry bulk market movements.
originally known as the Baltic Freight Index or BFI, the Baltic Dry Index replaced it on
November 1, 1999.
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