"I propose the redefinition of shares in such a way that the enticement of limitless price appreciation can be removed, and the primary market can take precedence over the secondary market.
The basic idea has to be to make borrowing money to gamble on the prices of existing shares a very unattractive proposition."
- Steve Keen 
A proposal for financial reform by Steve Keen, in the context of his argument, "Why We Need to Tackle Debt Pushing, not Money Creation":
"99% of all trading on the stock market involves speculators selling pre-existing shares to other speculators. This trading adds zip to the productive capacity of society, while promoting bubbles in stock prices because leverage drives up prices, encouraging more leverage, leading to a crash when price to earnings ratios reach levels even the Greater Fool regards as ridiculous. Then shares crash, but the debt that drove them up remains.
If instead shares on the secondary market lasted only 50 years, then even the Greater Fool couldn’t be enticed to buy them with borrowed money–since their terminal value would be zero. Instead a buyer would only purchase a share in order to secure a flow of dividends for 50 years (or less). One of the two great sources of rising unproductive debt would be eliminated.
I have to thank one of the participants at the AMI conference for inspiring a name for this proposal: Jubilee Shares, after the Biblical practice of abolishing debt every 50 years. There’s a twist to my proposal of course: it wouldn’t be a liability that was abolished but an asset, but the intent is to stop the liability of debt ever rising to the level where it would be a problem. So I suggest calling shares that last forever Jubilee Shares, while those that are on the secondary market are just ordinary shares that expire after 50 years.
Jubilee shares could be introduced very easily, if the political will existed–something that is still years away in practice. All existing shares could be grandfathered on one date, so that they were all Jubilee shares; but as soon as they were sold, they’d become ordinary shares with an expiry date of 50 years from the date of first sale." (http://www.debtdeflation.com/blogs/2010/10/04/jubilee-shares-and-the-american-monetary-act/)