From the Financial Times:
It is with interest, therefore, that we note Icap’s latest monthly shipping report — which errs towards the notion that the move wasn’t necessarily so unusual.As you can see from the graph from Stockcharts the BDI can be ... volatile.
According to the broker, for example, the BDI has fallen in June on 20 separate occasions since 1985 — making the recent declines relatively consistent.
As they noted:
..no other month can claim to have such a poor track record, although the month of July has shown a similar tendency towards weakness over the years.
It's important to know if a data series contains seasonal affects to it. That's one reason I tend to show data on a year over year format which eliminates time of year influences.