This is a BEARISH strategy, where an investor will sell an At the Money (ATM) or slightly In the Money (ITM) PUT then buy a deeper ITM PUT. Since the PUT that is purchased is deeper ITM, the transaction results in a net debit.
	BUY an ITM (In the Money) PUT.
	SELL a PUT one or more strikes below #1 PUT in the same month.
	The net investment or maximum risk is the net debit
	The maximum profit is realized if the stock is anywhere below the lowest strike price.
	The break even point is the higher strike price (#1) minus the net debit.
	Profit is realized when the stock price falls below the break even at or near expiration.
	Maximum profit is made when the stock price falls below the lower strike price (#2 PUT).
	Profit is achieved when both legs of the position are liquidated prior to expiration.
The return calculations for the Bear-Put Debit Spread are:
% Return =	Maximum profit / Net Investment
% Return =	(Difference in strikes - Net Debit) / Net Debit
Where...
Net Debit =	Premium on Bought PUT - Premium on Sold PUT
Example: Stock XYZ at $43.84 per share.
Buy the SEP 50 PUT for $6.70
Write (Sell) the SEP 45 PUT for $3.10
% Return =	(Difference in strikes - Net Debit) / Net Debit
% Return =	(50 - 45 - (6.70 - 3.10)) / (6.70 - 3.10) = 1.40 / 3.60 = 38.9%
Max. Risk =	Net Debit = 6.70 - 3.10 = $3.60, if stock is > $50 (both options would expire worthless and you would lose the entire Net Debit).
Max. Profit =	Difference in strikes - Net Debit = (50 - 45 - (6.70 - 3.10)) = $1.40, if stock is < $45.
Break Even =	Higher Strike - Net Debit = $50 - 3.60 = $46.40

XYZ at exp.	Long 50 PUT	Short 45 PUT	Spread Value	Spread Cost	Net
$55.00	0	0	0	-$3,600	-$3,600
$50.00	0	0	0	-$3,600	-$3,600
$46.40	$3,600	0	$3,600	-$3,600	0
$45.00	$5,000	0	$5,000	-$3,600	+$1,400
$40.00	$10,000	$5,000	$5,000	-$3,600	+$1,400

Profit and Loss values above assume a 10 contract position.

Advantages of this strategy:
	This is a BEARISH strategy, the profit can only be realized when the stock price falls from current price to a value below the break even point.
	If the stock goes very low gains are limited to the maximum profit above.
	Losses are limited to the net debit.
	No stock is actually owned (uncovered position).
	In the money (ITM) puts offer high break even points (more safety), but more limited profits.
	Out of the money puts offer larger profits, but have lower break even points, which require a fall in the price of the stock to realize gains.

Research Tips:
	If you like the risk/reward of the Debit Spread strategy but are bullish: Bull Call Debit Spreads Help
	If you are Bearish on the stock but prefer credit spreads: Bear Call Credit Spreads Help
	For more information on the Parity Strategy to Bear Put Debit spreads: Parity Trading - Option Spreads and Parity Option Trades Revisited

Bear Put Spreads - Bear Put Debit Spreads - Bear Put Option Spreads