There are ways to get loans where the only source of collateral are the underlying shares. For example, this is common when employees take loans out to cover the strike price of their options from their company.
Why do people feel they need to explain basic financial vehicles?
Obviously, you can get loans like this. Loans have interest, which means you must be able to generate future income suitable to cover this interest. Iger does not make enough in cash to cover the interest on a loan against his shares. Thus, he would have to generate the cash in some other way. The only foreseeable way he would have to do this is to sell disney shares, but this would cause the shares to decrease in value (and thus he would be unable to make up the principal payment). In order for such a loan to work, the loan would have to be so small as to be unimportant, or he would have to drive up the share price enough after the loan was written to make up the principle and interest, taking into account the imminent depression in share price if he attempts to sell that many shares.
Obviously, you can get loans like this. Loans have interest, which means you must be able to generate future income suitable to cover this interest. Iger does not make enough in cash to cover the interest on a loan against his shares. Thus, he would have to generate the cash in some other way. The only foreseeable way he would have to do this is to sell disney shares, but this would cause the shares to decrease in value (and thus he would be unable to make up the principal payment). In order for such a loan to work, the loan would have to be so small as to be unimportant, or he would have to drive up the share price enough after the loan was written to make up the principle and interest, taking into account the imminent depression in share price if he attempts to sell that many shares.