Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of dry bulk shipper Navios Maritime Holdings (NYSE:NM) leaped across the seas as much as 26.4% higher last week following an analyst upgrade and a sharply rising dry bulk rate environment.

So what: Research analysts at Stifel Nicolaus upgraded Navios Maritime Holdings from hold to buy and slapped a $14 price target on it. The analysts noted that iron ore prices have fallen recently which is causing Chinese steel producers to increase their orders and take advantage of the discount. These increased orders and shipments are causing a rally in shipping rates, especially the largest size Capesize ships.

The analysts added, "Furthermore with new iron ore mining capacity set to drive dry bulk shipping demand an estimated 5%-6% per year through 2016, we expect dry bulk shipping rates to improve, specifically for Capesize vessels."

Now what: Since Navios Maritime Holdings has 17 Capesize ships it is poised to benefit in a big way. Six of the ships operate based on the rising spot market and another six of those ships have their fixed-rate long-term contracts expiring this year and will presumably be put to work to take advantage of the spot market as well.

Stifel Nicolaus also notes that Navios Maritime Holdings has a "distinct advantage [that] positions them as one of the most leveraged names to rising dry bulk rates among U.S. listed names." The company also has 27 other smaller ships with expiring contracts in 2014 that should be rechartered at "significantly higher rates, providing the company with a good opportunity to grow earnings through a cyclical recovery in rates."

Star Bulk Carriers (NASDAQ:SBLK) described a similar situation for China and iron ore. The company noted that an expected increase in world iron mining volumes should continue to depress iron ore prices to levels that make domestically mined iron ore in China not viable. Star Bulk Carriers reasons the depressed mining volumes within China will necessitate increased import volumes which will cause a further spike in shipping rates, especially for Capesize ships. If true, this will have a greater impact on Navios Maritimes Holdings than on most other shippers.

Currently the average analyst estimate for Navios Maritime Holdings is $0.04 for 2014 and $0.78 for 2015. Look for these estimates to rise if Stifel Nicolaus and Star Bulk Carriers are correct. Last week the Baltic Dry Index shot up 22.7%, with the Capesize rates alone popping 43%, which gave investors the confidence that a strong 2014 is under way.