Short in Bollinger Band Down trend (Weekly and Daily)

// © PlanTradePlanMM
// 6/14/2020
// ---------------------------------------------------
// Name: Short in Bollinger Band Down trend (Weekly and Daily)
// ---------------------------------------------------
// Key Points in this study:
// 1. Short in BB Lower band, probability of price going down is more than 50%
// 2. Short at the top 1/4 of Lower band (EMA - Lower line), Stop is EMA, tartget is Lower line; it matches risk:/reward=1:3 naturally
//
// Draw Lines:
// BB Lower : is the Target (Black line)
// BB EMA : is the initial Stop (Black line)
// ShortLine : EMA - 1/4 of (Stop-target), which matches risk:/reward=1:3
// Prepare Zone : between EMA and ShortLine
// shortPrice : Blue dot line only showing when has Short position, Which shows entry price.
// StopPrice : Black dot line only showing when has Short position, Which shows updated stop price.
//
// Add SMA50 to filter the trend. Price <= SMA, allow to short
//
// What (Condition): in BB down trend band
// When (Price action): Price cross below ShortLine;
// How (Trading Plan): Short at ShortLine;
// Initial Stop is EMA;
// Initial Target is BB Lower Line;
// FollowUp: if price moves down first, and EMA is below Short Price. Move stop to EMA, At least "make even" in this trade;
// if Price touched Short Line again and goes down, new EMA will be the updated stop
//
// Exit: 1. Initial stop -- "Stop" when down first, Close above stop
// 2. Target reached -- "TR" when down quickly, Target reached
// 3. make even -- "ME" when small down and up, Exit at Entry Price
// 4. Small Winner -- "SM" when EMA below Entry price, Exit when Close above EMA
//
// --------------
// Because there are too many flags in up trend study already, I created this down trend script separately.
// Uptrend study is good for SPY, QQQ, and strong stocks.
// Downtrend Study is good for weak ETF, stock, and (-2x, -3x) ETFs, such as FAZ, UVXY, USO, XOP, AAL, CCL
// -----------------------------------------------------------------------------------------------------------------
// Back test Weekly and daily chart for SPY, QQQ, XOP, AAL, BA, MMM, FAZ, UVXY
// The best sample is FAZ Weekly chart.
// When SPY and QQQ are good in long term up trend, these (-2x, -3x) ETFs are always going down in long term.
// Some of them are not allowed to short. I used option Put/Put spread for the short entry.
//