The distinction Mr. Cuban makes is that in the Tech Bubble of 1999-2000 the tech companies were publicly traded, while today the tech companies (apps and small tech companies) are not. Mr. Cuban contends that investors in public companies during the Tech Bubble had liquidity - the ability to sell their stocks on the public market. Today, investors in these private companies have no liquidity, and so can't sell their stock if things turn south.
A second point he makes is that there are significant numbers of "Angel" investors investing in these companies and he first states that he thinks most of the investments made by these angels are under water because of the lack of liquidity. He then takes a jab at equity crowdfunding, the rules for which have not yet been finalized by the SEC, because he believes "there is no reason to believe that the SEC will be smart enough to create some form of liquidity for all those widows and orphans who will put their $5k into the dream only to realize they can't get any cash back when they need money to fix their car.
I respectfully disagree with much of Mr. Cuban's post. First, he assumes that we are in a bubble today, while I think there is lots of disagreement on this point. Please see my prior blog posts on this for more on whether we are in a bubble. Second, as the law stands today, it is mainly accredited investors who invest in these private companies. An accredited investor in the US is one who has net worth of $1 million (not including the value of their primary residence) or who has income of at least $200,000 each year for the last two years (or $300,000 together with their spouse if married). This seems to contradict Mr. Cuban's comment about these Angel investors not knowing what they have gotten into. Third, the Jumpstart Our Business Startups (JOBS) Act does provide for annual limits on investing through equity crowdfunding platforms. The Act provides that people earning under $100,000 the investing limit is the greater of $2,000 or 5% of their income. These limits suggest to me that the maximum losses incurred by "widows and orphans" should not be devastating.
I do agree that the lack of liquidity in private company securities means that it is harder to exit the investment, but my view is that sophisticated investors understand this already, and for unsophisticated investors there are protections in place already (and probably more to be included in the SEC rules) that will prevent them from betting the farm on a poor, illiquid investment.
Link to Mark Cuban's post:
http://blogmaverick.com/2015/03/04/why-this-tech-bubble-is-worse-than-the-tech-bubble-of-2000/
Links to prior posts on whether we are in a tech bubble:
http://www.allenlatta.com/allens-blog/are-we-in-a-venture-capital-bubble-more-thoughts
http://www.allenlatta.com/allens-blog/is-venture-capital-in-a-bubble
http://www.allenlatta.com/allens-blog/fred-wilson-on-the-bubble-question
http://www.allenlatta.com/allens-blog/tech-bubble-andreessen-and-conway-say-no
http://www.allenlatta.com/allens-blog/tech-bubble-two-views