I think the fashion for similarly marketed investments (including the infamous "an undertaking of great advantage but nobody to know what it is") is probably the biggest lesson.
That people in the seventeenth century didn't really understand how to value the fundamentals of a new government trade monopoly is unsurprising and its subsequent overvaluation perhaps not that great an indictment of seventeenth century investors; a more widely applicable lesson is that price movement in this stock spilled over into newfound speculator enthusiasm for absolutely ridiculous ventures and companies pretending to be raising money for one purpose and actually spending it on something else.
That people in the seventeenth century didn't really understand how to value the fundamentals of a new government trade monopoly is unsurprising and its subsequent overvaluation perhaps not that great an indictment of seventeenth century investors; a more widely applicable lesson is that price movement in this stock spilled over into newfound speculator enthusiasm for absolutely ridiculous ventures and companies pretending to be raising money for one purpose and actually spending it on something else.