5k share position? Hmm. maybe too big for just a single a position. As retail I would split it over multiple accounts, to hide the fact... As professional or institutional it's ok IMO.
To be fair, articles 1 and 2 are both unconfirmed anecdotal rants and appear to have nothing to do with a broker changing quotes. Article 3 is about a bucket shop unregulated overseas binary options "broker" which does not appear to be what the OP had in mind and which he/she wouldn't even be allowed to access if a U.S. citizen. Articles 4 and 5 are about high frequency traders, not brokers. Some of us actually read links, and without some kind of additional explanation the ones you provided do nothing to support your assertion any more than a link to a kitten video would. My assertion to all the tinfoil hat types like this is that if this behavior is truly going on, you're missing out on a chance to make huge sums of money. If you want to go long a stock, simply enter into a small long position. The broker will then, according to you, start sending fake quotes showing that the stock is tanking. You then take advantage of those quotes to load up on the full allocation of the stock you want at artificially fake low prices. So why aren't you out there making money off your broker's malfeasance? If you aren't going to do it, at least tell us the name of the broker where you observed this behavior personally so we can take advantage of it.
All online brokerage companies are bought out by online companies. Previously independent optionsXpress belongs to CharlsSchwab, Thinkorswim was bought by TD Ameritrade, eOptions belongs to Regal Securities and etc.Therefore under a broker below I will assume one of a portfolio managers of investment's institutions above. Why should they bother by a small day traders when if they manipulate they can get much bigger fish. 1.They may program and place counter orders to their clients' market orders to buy and sell with $0.01 difference. Lt's say I placed order to buy QQQ at market price and a broker buys it at $103.55 on market and sell it to me at $103.56. Wit huge number of orders it could be pretty solid income. Can they do it? - Yes. Do they do it? - I do not think so. It is traceable and under constant supervision it would be very difficult to cover... 2. Everybody know about "speed trading". Theoretically a broker (portfolio manager) has access to the broker's information may catch big volume orders and place counter buy/sell orders by the scenario described above in #1. Do they do it? Maybe, I am not sure, but, even if they do it they are not hunting me and you... 3. Broker has access to all buy sell orders before they are placed on the market. By itself this information is very valuable and under proper tools could be used in day trading. By having access to the deep information which is not available to regular traders a portfolio manager may build quite successful trading system. Do they do it? I think so. I already saw somewhere in Yahoo over the past couple of years reports when brokers payed "penny" settlements for using the orders info by some portfolio managers. 4. Broker-investor union gives unique ability to have "free advisory" services which may brag the only traders to buy/sell specific securities. This could be used by portfolio managers to dump to the public stocks they do not want to have in their portfolios. Does it happen? It is definitely the case. If you remember, there was some noise around Charles Schwab and Merril Lynch about dumping their housing and subprime mortgage investments to the traders who used them as a broker. My conclusion: Is the market manipulated? - yes, by those who has access. Does it affects me and you? No, it does not...
This brokerage set up a secret team that traded against its own clients: http://www.businessinsider.com/a-trading-team-at-itg-worked-against-the-brokers-clients-2015-8?IR=T "ITG, an electronic brokerage that trades more than 4 billion US shares a month, has admitted to running a secret trading desk that took advantage of its clients."
Again, this isn't the kind of gross manipulation of a quote feed for some guy's $5,000 account that the OP is worried about. It did happen, and Bernie Madoff ran a hedge fund that was a ponzi scheme. Both were uncovered, and it turns out the vast majority of hedge funds and brokers are honest businesses.
The following fraud is called "stop hunting". Here's the story of a victim: http://forums.babypips.com/newbie-island/42235-brokers-stop-hunting-trading-against-client.html "Bought Euro at 1.3060 / Stop Placed at 1.3045 (15 pips below price and 5 pips below pivot) No profit level placed,cos i will be out after 7/8 pips (depending on the day). After few ups and downs a quick down spike, took out my stop just 1 pip below at 1.3044, then price quickly went up again 5/6 pips to 1.3050, psychological level . All this is fine and a trader must put into account that some times things go wrong , the market is the boss and not what we think . However the charts platform of the live trade did not match the other free web charts offered by websites i use, and did not match what happened on the other platforms. On those charts the price never got to 1.3044, but it stopped exactly at 1.3050, and after bouncing for few mins, it went up to 1.3075/6" One should never place stop orders, instead should fire the close order only when its time has come. Ie. watch yourself the price action and act yourself, don't let your broker or the market know about your plan and intention... Automate such tasks at your side, not at the broker...
Again, not what the OP was posting and again, why couldn't you use that to your advantage to post a small trade with a stop and buy/short to your advantage when the "hunting" happens?
Do you think they haven't prevented such loopholes? They are the masters in this fraud, and they know exactly how to protect themselves. And are you so naive not to understand such crimes, and the fact that it is not that easy to prove? Just the existence of the term "broker trading against own clients" (--> google it) shows that there are very well such frauds committed...
That fraud is called "requoting": http://www.forextraders.com/forex-broker-tips/questionable-forex-broker-practices-explained.html " Requotes Requoting is the situation where your trading platform shows a trader a certain price and then when the trader goes to deal on it, the platform makes them wait. The platform then shows a different price for the trader's approval that is usually worse than the original price the trader had selected to deal on. "