Most people think time travellers support themselves by playing the stock market: you know, go back 30 years, buy low, then sell high in the "present" and you're all set, right? Such thinking merely betrays the chronoprovinciality of the time-locked, as if the traveller must only need money in the local now

In fact, time travellers have financial problems most people never dream of.

Consider first the fact that most forms of money are dated - I don't mean old, but stamped or printed with a date. This might not matter to a merchant, especially if the money is gold or silver, and it might not matter historically if the money is destroyed, as in burning (paper) or smelting (metal). The chance that one's money might cause a commotion, however, is a strong deterrent to anyone using anachronous dough. As noted in What Time Travellers Are Really Like, we always try to avoid attention.

How does a traveller avoid this? One way is to carry bullion gold or silver and trade it for coins locally. Another is simply to mint one's own coins or print one's own bills of the period. It isn't hard to duplicate the coins or bills of any era, though some consider this dishonest, especially in the case of paper, which has no intrinsic value. Needless to say counterfeiting is illegal everywhen, and if a traveller were ever discovered for what he truly is, his life would depend on whether the locals were more scared of counterfeiters from the future or more eager to get the secret of travel for themselves.

For the "honest" time traveller then (more honest than any government!) the metal exchange method is best. Some who are real moralizers will say this is tampering with the past, and the only way to ethically obtain wealth in past times is to trove up lost hordes or shipwrecks or, worse, work locally. Nevermind that they deprive later treasure hunters of their fortunes or local workers of their jobs, apparently. I'll assume you are not such a stick-in-the-mud and don't mind messing with History; after all, time travellers can't avoid it.

This takes care of the local cash problem. But people don't just spend cash; they have bills to pay, and for this they need banks. Even a time traveller, living safely isolated in Prehistory, will want local, historical flop houses and staging areas for his travels. How do you pay the bills when you don't know when you're going to be there?

Like any other rich person, you hire agents. A deposit in a bank sufficient to cover your bills (including the agent's fee) is easy: you just figure out how much is needed, then go back and make enough to cover it, either by stocks, commodities trading or (easiest) betting on horses. The final pay-off should coincide with your acquisition, so the bills are paid from that day on.

These bills are usually utility bills and property taxes, but rarely rent. Time travellers need privacy; we can't have anyone coming around asking nosey questions. For this reason, travellers like to own their Historical homes, not rent. Sometimes this is impractical, like if you want to live in a certain area that is all apartments. In that case, the traveller looks for a place where the management changes frequently or doesn't pay attention.

Also, there are time travellers who own apartment buildings and rent only to other travellers. These buildings tend to be old, so the traveller can come and go in a wide swath of time, and there is never a vacancy. Occasionally our secret slips out and someone tries to "crash" the building, or some official finds a reason to "inspect" it. We deal with this most severeelly.

With local cash easily obtained and our agents to pay our bills, are we home free? Not at all. There is also the large, one-time purchase to consider.

The problem with large, one-time purchases is that they can rarely be paid for in cash. Especially after 1990, any use of cash in quantities of more that a few thousand dollars at most will trigger a Federal investigation. Perhaps worse, the deal will be refused, as the merchant rightfully fears being labeled a "money launderer." The so-called "War On Drugs" which causes all this really seems to be a war on time travellers -- indeed there are those among us who believe it is exactly that.

You have to use banks. Easy enough you say, as travellers already use banks for paying bills. Yes, but bills are regular and predictable. When you don't know how much you'll need or when you'll need it, especially when you may spend from an account after you already spent from it in the future ... well, you can see the problem!

EXAMPLE: Say you put a million dollars in the bank in 1950. Ten years later, in 1960, it is worth $1.5 million; twenty years later, in 1970, it is worth $2 million. Now, in 1970 you spend $1 million of it, leaving $1 million. Let's say that, later in your own personal life but earlier in History, like in 1960, you spend a million from the same account. What happens?

You spent $1 million from the account in 1970. That account had grown from $1.5 in 1960. Now you've reduced that $1.5 million to only $500,000 by spending $1 million in 1960. Now the account will only have, perhaps, $700,000+ in it by 1970.

Egads! You've created a paradox!

Actually, you've created a tangle, but it's a problematic one. There would now be a universe where yourself (your other self) had deposited his $1 million in 1950 only to see it depleted by an interloper - YOU - before he could get to it. This sets up a war with yourselves. You can't all spend from the same account at different times!

To avoid tangling like this, the traveller must essentially finance every large purchase on its own. To buy an item costing $1 million, you don't write a check, because you don't have that much: most time travellers don't have personal checking accounts at all. Instead you go play the ponies again. Or, you buy bonds or certificates of deposit in a more cash-friendly era, cash them in for a line of credit just before your big buy, then do it that way.

You can also maintain a small account, deposit these sudden earnings in it just before you make the buy, then write a check which uses up the surplus. The advantage here is that you're not depending on a fixed amount being there at any given time; you're depositing the money just before you spend it via check. A credit card account can be used the same way.

Another problem for time travellers, and a reason we do not accumulate money in banks, is that of having too much money. An account which isn't drained of its surpluses (interest) for a long time becomes too big and attracts unwanted scrutiny. One of the first questions asked, since these accounts have usually existed for decades, is, "where is the original depositor?" You, being a perpetually youthful time traveller, cannot pass for him as he would have to be many times your apparent age. The account is locked up until you can convince them to release it. Of course the thing to do is go back and skim some off in the early years, but you still have the problem of what to do with your money.

It's a lot easier to finance your existence on a fly-by-night basis. This sounds disreputable, but it is the only way. After all, one thing that makes people "reputable" is their reliability over time, and you come and go at (it appears to them) random. By any normal standards, you are "disreputable."