If hedge fund investor capital is so hard to raise these days, shouldn’t managers take any capital they can get?  The short answer is, not if one dollar of investor capital costs two dollars in administrative fees, three dollars in litigation costs or four dollars in reputational impairment.  While ubiquitous in PPMs and thus largely ignored, hedge fund investment minimums nonetheless play an important role in hedge fund operations, marketing and portfolio management.  Such minimums communicate information about the manager, its investor base and its goals; both facilitate and constrain performance; impact the pace and quantity of capital raising; and influence the manager’s ability to manage liquidity.  Investment minimums are more important than generally understood, yet they have received a minimum of attention.  This two-part article series remedies that omission by focusing squarely and deeply on hedge fund investment minimums.  This article – the first in the series – outlines key legal, business, and investment rationales for setting hedge fund investment minimums.  Part two of this series will discuss market terms and trends for investment minimums as well as mechanics of implementing, enforcing, waiving and modifying minimum subscription amounts.