At the Internet Archive, an 1828 ‘Stranger’s Guide’ written by ‘Two Citizens of the World’ advises on how to avoid being swindled in London:
Swindling, when performed on a large scale, obtains the title of speculation. We need merely mention one word to remind our readers of the affinity between speculation and swindling – that one word is panic. Every one must remember the disastrous events of 1825, the era when every species of fraud was at its summit. […] In 1825, no less than one hundred and fifty companies were in existence – amongst them, how many now exist? not one-sixth.
More here.