With new silver streams already kicking in and major new additions looming large, the long-term-growth trajectory of Silver Wheaton (NYSE:WPM) looks effectively unstoppable.

With a phenomenal 26% year-over-year increase in attributable production volume during the third quarter of 2012 -- achieving another fresh company record of 7.7 million silver-equivalent ounces (SEOs) -- Silver Wheaton continues to construct one of the most noteworthy growth stories of the 21st century. Quarterly net profit slipped by 11% to $119.7 million as silver prices fell 14% over the period. But with a turbocharged net profit margin of 74%, this remains among of the most profitable companies in the world on that basis.

The awe-inspiring nature of the story comes into better view when we adjust for the portion of attributable silver produced during the quarter that was not reflected in third-quarter sales as a result of the timing of deliveries. For example, the company's brand-new stream deal with Hudbay Minerals (NYSE:HBM) spawned a welcome 733,000 SEOs of attributable production for the quarter, but none of that precious haul physically reached the company in time to be reflected within corresponding sales. Simultaneous delivery backlogs from Goldcorp's (NYSE:GG) Peñasquito mine and Glencore's Yualiyacu mine drove the cumulative delivery backlog higher by 2 million SEOs during the quarter to reach a total tally of 5.2 million ounces.

Applying the average realized sales price per SEO and the 74% net profit margin recorded during the quarter, we can crudely estimate that Silver Wheaton stands to record some $120 million in additional net profit -- or more still if the silver price continues to climb in the interim -- solely on the basis of ounces already produced and due to the company! As a long-term holder of Silver Wheaton's shares, I'm not merely unfazed by the growing backlog of attributable ounces; I actually welcome it! I remain convinced that gold and silver prices are headed substantially higher as the U.S. Federal Reserve continues to expand its balance sheet, and I am delighted by the prospect that those ounces will enjoy a higher average sales price than that realized in the third quarter. For similar reasons, I wholeheartedly applaud the ongoing and deliberate efforts of Endeavour Silver (NYSE:EXK) to periodically defer some portion of concentrate sales during bouts of relative weakness in silver prices in order to optimize shareholder returns.

With Silver Wheaton's 26% expansion of third-quarter production volume, the company remains solidly on track to reach 28 million SEOs for the full-year 2012. And even the silver streamer's 2016 target for 48 million SEOs -- representing a massive 90% growth explosion from 2011 output of 25.4 million SEOs -- is looking decidedly conservative. Well before 2016 rolls around, you can bet a silver dollar that CEO Randy Smallwood will have added new accretive stream purchases to his company's world-class fold to require upside adjustments to that target. Touting the company's gorgeous liquidity position of $955 million -- which rivals the acquisitive capacity of gold-focused counterpart Royal Gold (NASDAQ:RGLD) -- Smallwood remains "... excited about our potential to continue adding additional accretive ounces to our portfolio." I share his excitement, and continue to hold my shares of Silver Wheaton in anticipation of a $100 stock price by the time this precious metals bull market has run its full course.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.