Capesize spot rates have soared in recent weeks on tight Atlantic supply and robust Australian exports, but analysts question how long the rally will last.

The weighted timecharter equivalent (TCE) average for the iron-ore haulers has skyrocketed 811% to $29,395 per day since 29 May, according to Baltic Exchange assessments.

"This momentum has had a positive impact on the capesize period market where rates remained strong this week across both basins", Rebecca Galanopoulos Jones, commercial analyst for London-based ship brokerage Alibra Shipping told TradeWinds.