I have been playing around with this formula for an ATR trailing stop.

2 Questions.

1) How would I modify this formula to create the upper channel for a short position exit?

2) Is there any way to ratchet this so that once a high is reached it won't allow it to dip below that high.

MAXH22 - 3.5 * ((L < C1) * L + (L >= C1) * C1 - (H > C1) * H - (H <= C1) * C1 +
(L1 < C2) * L1 + (L1 >= C2) * C2 - (H1 > C2) * H1 - (H1 <= C2) * C2 +
(L2 < C3) * L2 + (L2 >= C3) * C3 - (H2 > C3) * H2 - (H2 <= C3) * C3 +
(L3 < C4) * L3 + (L3 >= C4) * C4 - (H3 > C4) * H3 - (H3 <= C4) * C4 +
(L4 < C5) * L4 + (L4 >= C5) * C5 - (H4 > C5) * H4 - (H4 <= C5) * C5 +
(L5 < C6) * L5 + (L5 >= C6) * C6 - (H5 > C6) * H5 - (H5 <= C6) * C6 +
(L6 < C7) * L6 + (L6 >= C7) * C7 - (H6 > C7) * H6 - (H6 <= C7) * C7 +
(L7 < C8) * L7 + (L7 >= C8) * C8 - (H7 > C8) * H7 - (H7 <= C8) * C8 +
(L8 < C9) * L8 + (L8 >= C9) * C9 - (H8 > C9) * H8 - (H8 <= C9) * C9 +
(L9 < C10) * L9 + (L9 >= C10) * C10 - (H9 > C10) * H9 - (H9 <= C10) * C10 +
(L10 < C11) * L10 + (L10 >= C11) * C11 - (H10 > C11) * H10 - (H10 <= C11) * C11 +
(L11 < C12) * L11 + (L11 >= C12) * C12 - (H11 > C12) * H11 - (H11 <= C12) * C12 +
(L12 < C13) * L12 + (L12 >= C13) * C13 - (H12 > C13) * H12 - (H12 <= C13) * C13 +
(L13 < C14) * L13 + (L13 >= C14) * C14 - (H13 > C14) * H13 - (H13 <= C14) * C14 +
(L14 < C15) * L14 + (L14 >= C15) * C15 - (H14 > C15) * H14 - (H14 <= C15) * C15 +
(L15 < C16) * L15 + (L15 >= C16) * C16 - (H15 > C16) * H15 - (H15 <= C16) * C16 +
(L16 < C17) * L16 + (L16 >= C17) * C17 - (H16 > C17) * H16 - (H16 <= C17) * C17 +
(L17 < C18) * L17 + (L17 >= C18) * C18 - (H17 > C18) * H17 - (H17 <= C18) * C18 +
(L18 < C19) * L18 + (L18 >= C19) * C19 - (H18 > C19) * H18 - (H18 <= C19) * C19 +
(L19 < C20) * L19 + (L19 >= C20) * C20 - (H19 > C20) * H19 - (H19 <= C20) * C20 +
(L20 < C21) * L20 + (L20 >= C21) * C21 - (H20 > C21) * H20 - (H20 <= C21) * C21 +
(L21 < C22) * L21 + (L21 >= C22) * C22 - (H21 > C22) * H21 - (H21 <= C22) * C22) / 22

Inverting your formula would involve adding 3.5 times a 22-Period Simple Moving Average of True Range:

MINL22 + 3.5 * ((AVGH22 - AVGL22) / 2 + (ABS(H - C1) + ABS(C1 - L) + ABS(H1 - C2) + ABS(C2 - L1) + ABS(H2 - C3) + ABS(C3 - L2) + ABS(H3 - C4) + ABS(C4 - L3) + ABS(H4 - C5) + ABS(C5 - L4) + ABS(H5 - C6) + ABS(C6 - L5) + ABS(H6 - C7) + ABS(C7 - L6) + ABS(H7 - C8) + ABS(C8 - L7) + ABS(H8 - C9) + ABS(C9 - L8) + ABS(H9 - C10) + ABS(C10 - L9) + ABS(H10 - C11) + ABS(C11 - L10) + ABS(H11 - C12) + ABS(C12 - L11) + ABS(H12 - C13) + ABS(C13 - L12) + ABS(H13 - C14) + ABS(C14 - L13) + ABS(H14 - C15) + ABS(C15 - L14) + ABS(H15 - C16) + ABS(C16 - L15) + ABS(H16 - C17) + ABS(C17 - L16) + ABS(H17 - C18) + ABS(C18 - L17) + ABS(H18 - C19) + ABS(C19 - L18) + ABS(H19 - C20) + ABS(C20 - L19) + ABS(H20 - C21) + ABS(C21 - L20) + ABS(H21 - C22) + ABS(C22 - L21)) / 44)

I do not know of a way to create a formula short enough to be practical which would not retreat.

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Great! Thanks Bruce.

You're welcome.