In the late 1980s and 1990s, the baseball card market experienced tremendous growth and speculation due to growing interest in collecting and investment potential. This led to severe overproduction of cards that has greatly diminished their value.

From the mid-1980s to early 1990s, the baseball card market boom was fueled largely by speculators who saw cards as an untapped investment opportunity. Major card manufacturers like Fleer, Topps, and Donruss ramped up production significantly to meet rising demand. From 1988 to 1995, annual baseball card production increased over 700% from approximately 400 million cards to over 3 billion cards printed annually.

This massive surge in printing was not matched by corresponding growth in the number of collectors. Most of these new printed cards ended up in the hands of investors and speculators hoping to quickly profit rather than collectors seeking to build lifelong collections. Speculation took priority over collecting for enjoyment and the growing attachment to specific athletes and teams that had sustained earlier baseball card markets.

At the same time, new premium and insert cards were introduced featuring autographs, rare parallels, die-cuts and other gimmicks to entice speculators. These special cards soaked up much of the available disposable income that formerly supported the broader card market. With speculators chasing these premium cards, demand and prices dropped significantly for most straightforward base cards featuring common players.

By the mid-1990s, the baseball card speculative bubble had fully burst. With an enormous card glut, prices crashed and speculators fled the market. The overall enthusiasm and dedicated collector base also diminished as children had many new entertainment options competing for their time and money like video games, movies and toys. This drop in core collecting demand further weakened the baseball card market.

Meanwhile in the 1990s, the rising influence of technology also impacted baseball cards negatively. The internet made card values and print runs transparent for the first time. This eliminated much of the potential for insider knowledge and secret finds that had sustained speculation. It also gave rise to online piracy as images were copied and shared freely. The physical and emotional bond to cardboard cards diminished as digital collections and virtual sports games emerged.

A major consequence of the boom and bust was that 1990s card production far outstripped any collector demand sustained over the long term. Even for popular stars, 1990s base cards exist in astonishing numbers rarely commanding more than a dollar even in top condition. Frank Thomas rookies? Michael Jordan baseball cards? Mike Piazza or Ken Griffey Jr.? All can be regularly acquired for under $5 because they were simply printed in such incredible quantities.

Many printing techniques from the 1990s such as heavy gloss and dark borders date the aesthetics of the cards. They lack the clean, timeless designs of earlier decades that have helped maintain interest. Poor storage and mishandling over 25 years has also taken a toll on many 1990s cardboard survivors. So they hold little nostalgic charm or appeal to new collectors.

The unchecked speculation, immense overproduction, fleeting fads, maturation of kids trading cards for tech, greater transparency and accessibility all combined in the 1990s to create a baseball card market disaster whose aftereffects linger still. Supply vastly overwhelmed any sustainable demand for most 1990s players and issues keeping prices for nearly all incredibly low. It serves as a cautionary lesson for any collector market based more on gambling than appreciation.

So in conclusion, the confluence of factors from speculation to printing to cultural shifts ensures that aside from the best rookie cards of all-time performers or truly scarce variants, most 1990s baseball cards have essentially no monetary value due to being abundantly, ubiquitously available for under $5 in raw, ungraded condition if that. They remain collectibles for their historic or sentimental appeal alone.