You can read about it here ....

You can read about it here . https://www.miningtaxcanada.com/flow-through-shares/

there is even a worked example of how they buy the overprice share and claim an immediate deduction and then with the sell at market price (lower) they make more than they paid.

Table 1 sets out a simple example illustrating the consequences to a FTS investor who purchases 10,000 FTS of a mining company at a $1/share premium over the trading price of the “ordinary” (non-FTS) common shares of FTS Issuer, and later sells them into the market at the prevailing trading price.

TABLE 1: FTS CASH-FLOW EXAMPLE

Assumptions
Flow-through shares purchased		10,000
Price per FTS		$10
FTS Issuer regular common share trading price		$9
FTS premium per share		$1
Investor’s federal /provincial tax rate		46%
CEE renounced per FTS		$10
..
	Investor Cash Out	Investor Cash In
Cost of FTS ($10/share)	$100,000
Tax savings from $100,000 renounced CEE		$ 46,000
Investor’s proceeds from selling FTS in market		$ 90,000
Tax owing on capital gain from sale of FTS	$ 20,700	________
	$120,700	$136,000
Investor’s positive cash flow		$ 15,300

if the shorter are supposedly BoA or JPMorgan then I imagine they are not from Canada and won’t get the shares