The following commentary comes from an independent investor or market observer as part of TheStreet's guest contributor program, which is separate from the company's news coverage. NEW YORK ( Trefis) -- Sprint's ( S) stock tumbled to its lowest in almost two years after seven analysts lowered their estimates following the carrier's investor meeting where it laid out a roadmap for the launch of its wireless LTE network. Among others, Kaufman Brothers, Deutsche Bank, Collins Stewart, JP Morgan, and Atlantic Equities cut their ratings to neutral or the equivalent while Raymond James cut its rating on the stock to outperform from strong buy. The stock did get some reprieve Tuesday and recovered a little over 5%. At Monday's close, the stock had fallen by 7.9% to end the day at $2.22, which is nearly half our $4.73 price estimate on this stock. This is in contrast to the broader market rising by around 3.5%. See our complete analysis for Sprint stock here. At its Oct. 7 meeting, Sprint had indicated its plans to take on additional debt to fund the rollout of their new higher-speed 4G LTE network by mid-2012. It had also earlier announced unlimited data plans for iPhone users. We believe that if the company is able to lure iPhone users with its uncapped data plans and at the same time increase speeds and reduce costs by using its LTE network, the long-term prospects of the company looks good. However liquidity concerns arising from excessive debt on its balance sheet will continue to be a major deterrent to its business, and should this strategy not pay off, Sprint could be in dire straits. Sprint also announced yesterday that it has sold out of pre-orders for both the white and black versions of the 16GB iPhone 4S. It seems the market is unwilling to acknowledge this news in Sprint's favor. We believe this is either because of fears that the margins on the iPhone sales will not be good or that the debt overhang of the iPhone deal and the cost of the LTE upgrade will overwhelm any positives from the iPhone in the near term. Like our charts? Embed them in your own posts using the Trefis Wordpress Plugin.