gone parabolic

[Victor Steinbok]

An odd line in a WSJ blog post on the Netflix stock success:

http://goo.gl/lDRff
> The chart on Netflix has truly /gone parabolic/ since late January 2010.

Take a look at NFLX stock charts and see for yourself if there is
anything "parabolic" about them.

http://goo.gl/yRpTz

Although the stock price has been rising fairly steadily over the past
11 months (starting from a 1-year low on Jan. 2), the rise has been
fairly close to linear (with some daily and weekly fluctuations, of
course, e.g., a small drop today). But looking at 3-yr and 5-yr charts
shows that the price had been fairly flat for a long time through
October of 2008, then crept up slowly to the end of 2009 (from high
10s-low 20s to about $50), and rose much more rapidly in 2010 ($50 to
$209, having hit $100 in May and August, August being the last "dip").
There is little doubt that one could fit a parabola to the data, but
that does not necessarily make the chart "parabolic" (of course, one
could "fit" a parabola to /any/ chart, with different degrees of
accuracy). Besides, the claim is not that the chart is parabolic over
the last 3-5 years, but over the last 11 months, when the growth can
best be described as linear!

The question I have is whether this may represent simply an attempt to
communicate a pattern of sharper increases over shorter periods of time
(which, I suspect, most investors would not understand--and is not true
for the specifically mentioned period) or if the term "parabolic" has
simply gone hyperbolic, like the much belabored "exponential" (with the
difference being a question of degree--and I don't mean that to be the
degree of a polynomial). What throws me off is the use of "truly" in the
quoted sentence, but, of course, this may not truly mean "truly" (see,
for example, all the past threads on "literally" in ADS-L archives). I
am generally fascinated by odd usage of fairly well-defined mathematical
terms, so this one grabbed me right away.

There is another reference in the post which is common, but not always
comprehensible:

> Where are you? Buying at these levels? Even when the charts alone
> could give you a nosebleed?

"Nosebleed" is also in the subject line. This may mean one of several
things, most having to do with heights. There is, of course, the
"nosebleed seats" at sporting venues (or concert halls), which follows
the only slightly more general definition in OED nosebleed 2.b.:

> [2.]b. colloq. (orig. U.S.) (humorous). attrib. Denoting places or
> situations characterized as likely to cause nosebleed due to excessive
> altitude or speed, esp. the highest (and cheapest) seats in an
> auditorium or stadium.

Since the original use as figurative to begin with, this one is doubly
so--since it does not refer to the actual heights. But this is nowhere
as interesting as "parabolic".

     VS-)

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