Re: [amibroker] Re: Buying at open -- In Real Life

[Mark H]

Limit shares by % of one bar's volume is one of the worst practices in backtesting. I am always a bit puzzled by why everybody is concerned about "looking into the future" but few people pay attention to this practice. It is "looking into the future" in terms of volume! When you place an order in the morning, do you know today's volume? And position sizing has great impact on system performance.   Anyway, to use 1% EMA(V,50) of today as limit for tomorrow's entry, you may need to use CBT to do backtest. Here is what I do: (normal position size is 10% of equity)   ...... SetPositionSize(EMA(V,50) * 0.01 * BuyPrice, spsValue ); ...... if( Status("action") == actionPortfolio ) { bo = GetBacktesterObject(); .......... for ( sig=bo.GetFirstSignal(bar); sig; sig=bo.GetNextSignal(bar)) { // Only one position per symbol if (sig.isEntry() AND sig.Price != -1 AND IsNull( bo.FindOpenPos( sig.Symbol ))) { // sig.PosSize is passed from Phase I. It is %1 of EMA(V, 50). ps = Min(sig.PosSize, bo.Equity * 0.10); // long only bo.EnterTrade(bar, sig.symbol, True, sig.Price, ps, sig.PosScore,sig.RoundLotSize); } }     ----- Original Message ----- From: intermilan04 To: amibroker@yahoogroups.com Sent: Tuesday, August 15, 2006 11:37 PM Subject: [amibroker] Re: Buying at open -- In Real Life Hi Mark, Very interesting approach. How do you limit the volume like how you do? I am aware you can limit by % of one bar's volume, but not sure if you could do like 1% of 50 period EMA of volume. Regards, intermilan04 --- In [EMAIL PROTECTED]ps.com, "Mark H" <[EMAIL PROTECTED]..> wrote: > > Yes. My system buys/sells at open since I still have a day job. The results have been very close to those of backtest. > I think it contribute to two factors: I use IB which in most cases can get you the exact open prices; my system limits the shares to buy to 1% of 50 period EMA of volume. > > ----- Original Message ----- > From: intermilan04 > To: [EMAIL PROTECTED]ps.com > Sent: Tuesday, August 15, 2006 2:30 AM > Subject: [amibroker] Buying at open -- In Real Life > > > Hi all, > > I'm just curious if anyone here are buying and selling securities at > the open with market orders, i.e. orders are placed BEFORE MARKET OPEN > and they get executed as soon as the market opens. > > I have noticed that buying at the open might help you get cheap > shares, but the reverse is also true...you might sell your shares at > really bad bids. > > The reason why I'm bringing it up is, my system on Amibroker is > designed to trade at the open. And strangely enough, my system isn't > doing too well ever since I started using it...perhaps it's because > I'm getting bad bids and asks by placing market orders overnight? > > I'm not quite sure how the first trade occurs, in theory I sell to the > highest bidder but with low liquidity of pre-market trading, what if > the highest bid is absurdly low? > > Any thoughts on this is greatly appreciated. > > Regards, > > intermilan04 > __._,_.___ Please note that this group is for discussion between users only. To get support from AmiBroker please send an e-mail directly to SUPPORT {at} amibroker.com For other support material please check also: http://www.amibroker.com/support.html YAHOO! GROUPS LINKS  Visit your group "amibroker" on the web.    To unsubscribe from this group, send an email to:  [EMAIL PROTECTED]    Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. __,_._,___