The Nasdaq composite index dipped into negative territory at moments, but closed up 4.62 points, or 0.19 percent, at 2,402.58.
In the euro zone, for instance, the main interest rate is at 0.05% but the "real" (or adjusted for inflation) interest rate is considerably higher, at 0.65%, because euro-area inflation has dropped into negative territory at -0.6%.
If the European Central Bank, desperately trying to generate inflation and stimulate lending, takes a further step into negative territory at its meeting next month, would the woes of Deutsche and the banking sector deepen?
"It is a well-known fact that positive response often turns into negative response at a certain point," she said, noting that leaves sprouting earlier in the year may expand the carbon-uptake period, but then increase the risk of frost damage.
After opening slightly higher the major indexes were edging into negative territory at midday and trading in a narrow range.
The Scottish Chambers of Commerce said it was disappointing that exports dipped into negative territory at the beginning of this year.
The Dow Jones Industrial Average rose 2.84 to 9184.27, while the S&P 500 slipped into negative territory at the end of the session, losing 1.13 to 1228.10.
After a wild day on Wall Street, the major indexes settled into negative territory at Tuesday's close, but recovered a bulk of the day's losses.
Same-store sales growth for the fourth quarter slowed to 0.7% versus 4.6% the year earlier, while growth in sales per square foot fell into negative territory, at -0.1% from a 3.7% gain before.
