When I changed my currency (GBP->Yen), I got it from Travelex (I didn't go for Thomas Global because I thought I couldn't get them to ship to my work's address). I decided to get the Buy Back offer (for £4m they buy your unsued currency at the same rate), so I now have a receipt that will allow me to change upto Y301,000 back at a rate of around 138 (or there abouts).

Now, I have noticed that the rate has jumped up recently, and was wondering if I could use this to my advantage. If I were to convert more GBP to Yen (by ordering to collect from Travelex like last time) at the higher rate, and then to change all my Yen back at the lower rate, I should in theory make a bit of money. Am I missing something with this plan or does anyone know anything more about it? I've already spent over Y100,000 just on accomodation, and should have spent at least Y200,000 by the end of the holiday.

E.g.
At the higher rate, I order: -
£1399 @ 143 = Y200,000
Then, using my Buy Back receipt, I change it back: -
Y200,000 @ 138 = £1449

So I would make £50. Not much I know, but in theory it's for doing nothing. It would also dpend on the rate at the time I decide to do this. It seems to have leveled for now. Annoyingly, I should have brought more GBP cash with me (only have £30), I saw exhange rates of about 157 here today!