Sorry, not silly -
Delta is an idea that Welles-Wilder bought into and now sells. Without giving too much away a chap persuaded W-W that markets repeat their behaviour on a regular basis, so for example you can take a chart of the Dow 30 and pick out highs and lows, then work out the dates when those highs and lows will repeat. You could pick out a pattern of these reversals in trend for a sector and find that the sector components repeated the sector pattern, ie you find the dates for the tops and bottoms in the chip sector and a year from now you have a good idea of when AMD will peak.
This is held to be true for all markets and a variety of timeframes - timeframes run from intraday moves ("stand by, INTC is going to peak at 2pm" sort of thing) to very long term - as I recall the Dow is part way through the second repeat of a cycle that lasts a century or so... picka share, sector, or entire market and then combine it with a timeframe of hours, to days, to weeks, months...decades......
It's easy to convince yourself it works - many top/bottom forecast turns occur on the money - you can't be sure that the move is obvious at the time, and profitability may depend on spotting the entry and exit when neither is obvious when the money is on the table. I could provide Dow, SP500 (this is US oriented, although with effort you could make it UK friendly) charts where even the most cynical would have to admit the turns were uncannily accurate considering they were forecast months or years in advance. However - consider this.....
Look at a bar/candle chart, see how obvious it is where the tops and bottoms are? Now look at the last bar - is it a top or a bottom or neither? AFTER the event you find the turn was forecast within maybe 3-4 days, or even spot on... but you don't know that at the time the top/bottom actually occurs. In reality TA isn't about finding entry.exit signals, it is about extracting the profit from those that pan out whilst swiftly exiting those that don't - the buy/sell signal is almost inconsequential.
Delta costs about £200, a bit less, for the book that describes it all. To actually trade the signals you really need the software because it's a complete pain otherwise - I program trading software, I wrote a 'Delta' program, and I can't be bothered to do all the work involved to reproduce it. For a non-programmer trust me, you'l buy the software if you buy into the idea.
The software costs a few $k, this does not give you intraday signals - longer timeframes yes. Intraday info is for 'directors' only, which (last special offer) was about $10k as I recall. For EoD traders intraday is immaterial, and for what it's worth I consider the medium term info more use anyway - I'm ignoring the shorter term info that is 'longer term than the intraday info'.
If you buy the software you then pay a couple of hundred bucks a year to stay turned on - the software turns itself off when it times out. TCI and a few other 'extras' cost on top of the rental. Delta is not cheap.
The inventor (?) has, since flogging it to W-W, produced a new version - based on tide tables I think. You can buy that instead - Jim Sloman is his name.
Final take: There is substance in it, but it is difficult to turn what is undoubtedly a good turn point predictor into a profitable system - the guy writing the official newsletter has trouble persuading me he is in profit, in fact his 'closed trades' record sucks. If the guy responsible for drumming up interest can't make a profit..... Secondly you can't help but wonder, as with most systems, how the seller isn't just trading it and spending the other 38 working hours a week burying the profits under the roses. I consider Delta to be another step on my personal road to knowing everything - I long since decided that perfect knowledge doesn't equal profit, so I pursue profit and knowledge seperately these daya - one for interest, the other for the Netjets subs.
As a bonus, if you buy the book "The Delta Phenomenon" you get a free copy of Welles-Wilder's book on amassing wealth, that tells you to trade what you know and rely on compound interest, it does this over more pages than you can shake a stick at in a cringingly badly written style that assumes (I guess) monkeys have learned to read, here's the book for them... it is DIRE, as one reviewer once wrote "this is not a book to be put aside lightly, it should be thrown with great force". I've donated mine to the local charity shop, had I written it I would even now be scratching my gold embossed name from the spine....
Dave